CGRP Receptor Antagonists

ABSTRACT

The disclosure generally relates to the novel compounds of formula I, including pharmaceutically acceptable salts, which are CGRP receptor antagonists. The disclosure also relates to pharmaceutical compositions and methods for using the compounds in the treatment of CGRP related disorders including migraine and other headaches, neurogenic vasodilation, neurogenic inflammation, thermal injury, circulatory shock, flushing associated with menopause, airway inflammatory diseases such as asthma, and chronic obstructive pulmonary disease (COPD).

CROSS-REFERENCE TO RELATED APPLICATIONS

This Continuation application claims the benefit of U.S. Ser. No.12/902,714 filed Oct. 12, 2010, now allowed, which in turn claims thebenefit of U.S. Provisional Application Ser. No. 61/251,477 filed Oct.14, 2009, now expired.

BACKGROUND OF THE INVENTION

The disclosure generally relates to the novel compounds of formula I,including pharmaceutically acceptable salts, which are CGRP-receptorantagonists. The disclosure also relates to pharmaceutical compositionsand methods for using the compounds in the treatment of CGRP relateddisorders including migraine headaches, neurogenic vasodilation,neurogenic inflammation, thermal injury, circulatory shock, flushingassociated with menopause, airway inflammatory diseases such as asthma,and chronic obstructive pulmonary disease (COPD).

Calcitonin gene-related peptide (CGRP) is a naturally occurring37-amino-acid peptide first identified in 1982 (Amara, S. G. et al,Science 1982, 298, 240-244). Two forms of the peptide are expressed(αCGRP and βCGRP) which differ by one and three amino acids in rats andhumans, respectively. The peptide is widely distributed in both theperipheral (PNS) and central nervous system (CNS), principally localizedin sensory afferent and central neurons, and displays a number ofbiological effects, including vasodilation.

When released from the cell, CGRP binds to specific cell surface Gprotein-coupled receptors and exerts its biological action predominantlyby activation of intracellular adenylate cyclase (Poyner, D. R. et al,Br J Pharmacol 1992, 105, 441-7; Van Valen, F. et al, Neurosci Lett1990, 119, 195-8.). Two classes of CGRP receptors, CGRP1 and CGRP2, havebeen proposed based on the antagonist properties of the peptide fragmentCGRP (8-37) and the ability of linear analogues of CGRP to activateCGRP2 receptors (Juaneda, C. et al. TiPS 2000, 21, 432-438). However,there is lack of molecular evidence for the CGRP2 receptor (Brain, S. D.et al, TiPS 2002, 23, 51-53). The CGRP1 receptor has three components:(i) a 7 transmembrane calcitonin receptor-like receptor (CRLR); (ii) thesingle transmembrane receptor activity modifying protein type one(RAMP1); and (iii) the intracellular receptor component protein (RCP)(Evans B. N. et al., J Biol. Chem. 2000, 275, 31438-43). RAMP1 isrequired for transport of CRLR to the plasma membrane and for ligandbinding to the CGRP-receptor (McLatchie, L. M. et al, Nature 1998, 393,333-339). RCP is required for signal transduction (Evans B. N. et al., JBiol. Chem. 2000, 275, 31438-43). There are known species-specificdifferences in binding of small molecule antagonists to theCGRP-receptor with typically greater affinity seen for antagonism of thehuman receptor than for other species (Brain, S. D. et al, TiPS 2002,23, 51-53). The amino acid sequence of RAMP1 determines the speciesselectivity, in particular, the amino acid residue Trp74 is responsiblefor the phenotype of the human receptor (Mallee et al. J Biol Chem 2002,277, 14294-8).

Inhibitors at the receptor level to CGRP are postulated to be useful inpathophysiologic conditions where excessive CGRP receptor activation hasoccurred. Some of these include neurogenic vasodilation, neurogenicinflammation, migraine, cluster headache and other headaches, thermalinjury, circulatory shock, menopausal flushing, and asthma. CGRPreceptor activation has been implicated in the pathogenesis of migraineheadache (Edvinsson L. CNS Drugs 2001; 15(10):745-53; Williamson, D. J.Microsc. Res. Tech. 2001, 53, 167-178.; Grant, A. D. Brit. J. Pharmacol.2002, 135, 356-362.). Serum levels of CGRP are elevated during migraine(Goadsby P J, et al. Ann Neurol 1990; 28:183-7) and treatment withanti-migraine drugs returns CGRP levels to normal coincident withalleviation of headache (Gallai V. et al. Cephalalgia 1995; 15: 384-90).Migraineurs exhibit elevated basal CGRP levels compared to controls(Ashina M, et al., Pain 2000, 86(1-2):133-8.2000). Intravenous CGRPinfusion produces lasting headache in migraineurs (Lassen L H, et al.Cephalalgia 2002 February; 22(1):54-61). Preclinical studies in dog andrat report that systemic CGRP blockade with the peptide antagonist CGRP(8-37) does not alter resting systemic hemodynamics nor regional bloodflow (Shen, Y-T. et al, J Pharmacol Exp Ther 2001, 298, 551-8). Thus,CGRP-receptor antagonists may present a novel treatment for migrainethat avoids the cardiovascular liabilities of active vasoconstrictionassociated with non-selective 5-HT1B/1D agonists, ‘triptans’ (e.g.,sumatriptan).

CGRP antagonists have shown efficacy in human clinical trials. See DavisC D, Xu C. Curr Top Med. Chem. 2008 8(16):1468-79; Benemei S, NicolettiP, Capone J G, Geppetti P. Curr Opin Pharmacol. 2009 9(1):9-14. Epub2009 Jan. 20; Ho T W, Ferrari M D, Dodick D W, Galet V, Kost J, Fan X,Leibensperger H, Froman S, Assaid C, Lines C, Koppen H, Winner P K.Lancet. 2008 372:2115. Epub 2008 Nov. 25; Ho T W, Mannix L K, Fan X,Assaid C, Furtek C, Jones C J, Lines C R, Rapoport A M; Neurology 200870:1304. Epub 2007 Oct. 3.

CGRP receptor antagonists have been disclosed in PCT publications WO2004/092166, WO 2004/092168, and WO 2007/120590.

The invention provides technical advantages, for example, the compoundsare novel and inhibit CGRP. Additionally, the compounds provideadvantages for pharmaceutical uses, for example, with regard to one ormore of their mechanism of action, binding, inhibition efficacy, targetselectivity, solubility, safety profiles, or bioavailability.

DESCRIPTION OF THE INVENTION

The invention encompasses a series of CGRP antagonist compoundsincluding pharmaceutically acceptable salts, compositions, methods ofmaking them, and methods of using them in therapeutic treatment.

One aspect of the invention is a compound of formula I

where:R¹ is hydrogen, cyano, halo, alkyl, haloalkyl, alkoxy, amino,alkylamino, dialkylamino, azetidinyl, pyrrolidinyl, or piperidinyl;R² piperidinyl substituted with 1 substituent selected from the groupconsisting of

or R² is

R³ is hydrogen, halo, cyano, alkyl, haloalkyl, alkoxy, or haloalkoxy;R⁴ is hydrogen, halo, cyano, alkyl, haloalkyl, alkoxy, or haloalkoxy;R⁵ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R⁶ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R⁷ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R⁸ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R⁹ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R¹⁰ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R¹¹ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,dialkylamino, alkoxycarbonyl, or benzyloxycarbonyl;or R¹⁰ and R¹¹ taken together is O or N—OH;provided that at least one of R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, or R¹¹ is nothydrogen;Ar¹ is phenyl substituted with 0-3 substituents selected from the groupconsisting of cyano, halo, alkyl, haloalkyl, alkoxy, haloalkoxy, andalkylSO₂;

X is O, CH₂, or NH; and

Y is a bond, O, CH₂, or NH;or a pharmaceutically acceptable salt thereof.

Another aspect of the invention is a compound of formula I where:

R¹ is hydrogen, cyano, halo, alkyl, haloalkyl, alkoxy, amino,alkylamino, dialkylamino, azetidinyl, pyrrolidinyl, or piperidinyl;R² is piperidinyl substituted with 1 substituent selected from the groupconsisting of

or R² is

R³ is hydrogen, halo, cyano, alkyl, haloalkyl, alkoxy, or haloalkoxy;R⁴ is hydrogen, halo, cyano, alkyl, haloalkyl, alkoxy, or haloalkoxy;R⁵ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R⁶ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R⁷ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R⁸ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R⁹ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R¹⁰ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;R¹¹ is hydrogen, hydroxy, alkoxy, haloalkoxy, azido, amino, alkylamino,or dialkylamino;or R¹⁰ and R¹¹ taken together is oxo;provided that at least one of R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, or R¹¹ is nothydrogen;Ar¹ is phenyl substituted with 0-3 substituents selected from the groupconsisting of cyano, halo, alkyl, haloalkyl, alkoxy, haloalkoxy, andalkylSO₂;

X is O, CH₂, or NH; and

Y is a bond, O, CH₂, or NH;or a pharmaceutically acceptable salt thereof

Another aspect of the invention is a compound of formula I with thedesignated stereochemistry.

Another aspect of the invention is a compound of formula I where

R¹ is hydrogen, halo, cyano, amino, alkylamino, or dialkylamino;R² is piperidinyl substituted with 1 substituent selected from the groupconsisting of

R³ is hydrogen or halo;R⁴ is hydrogen or halo;R⁵ is hydrogen or hydroxy;R⁶ is hydrogen;R⁷ is hydrogen;R⁸ is hydrogen;R⁹ is hydrogen or hydroxy;R¹⁰ is hydrogen, hydroxy, azido, amino, alkylamino, or dialkylamino;R¹¹ is hydrogen;or R¹⁰ and R¹¹ taken together is oxo;provided that at least one of R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, or R¹¹ is nothydrogen;Ar¹ is phenyl substituted with 0-2 halo substituents;

X is O, CH₂, or NH; and Y is O;

or a pharmaceutically acceptable salt thereof.

Another aspect of the invention is a compound of formula I where R¹ ishydrogen; R² is piperidinyl substituted with 1 substituent selected fromthe group consisting of

R⁵ is hydrogen or hydroxy; R⁶ is hydrogen; R⁷ is hydrogen; R⁸ ishydrogen; R⁹ is hydrogen or hydroxy; R¹⁰ is hydroxy, azido, or amino;R¹¹ is hydrogen; or R¹⁰ and R¹¹ taken together is oxo; provided that atleast one of R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, or R¹¹ is not hydrogen; Ar¹ isphenyl or difluorophenyl; X is O, CH₂, or NH; and Y is O; or apharmaceutically acceptable salt thereof.

Another aspect of the invention is a compound of formula I where R¹ ishydrogen, cyano, halo, alkyl, haloalkyl, alkoxy, amino, alkylamino,dialkylamino, azetidinyl, pyrrolidinyl, or piperidinyl.

Another aspect of the invention is a compound of formula I where R² isN-piperidinyl and is 4-substituted. Another aspect of the invention is acompound of formula I where the substituent is

Another aspect of the invention is a compound of formula I where R⁵ ishydrogen, R⁶ is hydrogen, R⁷ is hydrogen, R⁸ is hydrogen, R⁹ ishydrogen, R¹⁰ is hydroxy, azido, or amino, and R¹¹ is hydrogen; or whereR⁵ is hydrogen, R⁶ is hydrogen, R⁷ is hydrogen, R⁸ is hydrogen, R⁹ ishydrogen or hydroxy, and R¹⁰ and R¹¹ taken together is oxo; or where R⁵is hydrogen, R⁶ is hydrogen, R⁷ is hydrogen, R⁸ is hydrogen, R⁹ ishydroxy, R¹⁰ is hydrogen or hydroxy, and R¹¹ is hydrogen; or where R⁵ ishydroxy, R⁶ is hydrogen, R⁷ is hydrogen, R⁸ is hydrogen, R⁹ is hydrogen,R¹⁰ is hydrogen, and R¹¹ is hydrogen.

Another aspect of the invention is a compound of formula I where Ar¹ isphenyl substituted with 2 halo substituents.

Another aspect of the invention is a compound of formula I where Ar¹ is2,3-difluorophenyl.

Another aspect of the invention is a compound of formula I where X is O.

The scope of any instance of a variable, including R¹, R², R³, R⁴, R⁵,R⁶, R⁷, R⁹, R¹⁰, or R¹¹, Ar¹, X and Y, can be used independently withthe scope of any other instance of a variable substituent. As such, theinvention includes combinations of the different aspects.

Unless specified otherwise, these terms have the following meanings.“Alkyl” means a straight or branched alkyl group composed of 1 to 6carbons, preferably 1 to 3 carbons. “Alkenyl” means a straight orbranched alkyl group composed of 2 to 6 carbons with at least one doublebond. “Cycloalkyl” means a monocyclic ring system composed of 3 to 7carbons. “Hydroxyalkyl,” “alkoxy” and other terms with a substitutedalkyl moiety include straight and branched isomers composed of 1 to 6carbon atoms for the alkyl moiety. “Haloalkyl” and “haloalkoxy” includeall halogenated isomers from monohalo substituted alkyl to perhalosubstituted alkyl. “Aryl” includes carbocyclic and heterocyclic aromaticring systems. “Amino” includes includes primary, secondary, and tertiaryamine moieties. “Carbonyl” means CO. “Oxy” means —O—. “Aminocarbonyl”means —N(R)C(═O)—. “Oxycarbonyl” means —OC(═O)—. “Methylenecarbonyl”means —CHYDROGENC(═O)—. “Amino(cyano)iminomethyl” means —NHC(═NCN)—.Parenthetic and multiparenthetic terms are intended to clarify bondingrelationships to those skilled in the art. For example, a term such as((R)alkyl) means an alkyl substituent further substituted with thesubstituent R.

The invention includes all pharmaceutically acceptable salt forms of thecompounds. Pharmaceutically acceptable salts are those in which thecounter ions do not contribute significantly to the physiologicalactivity or toxicity of the compounds and as such function aspharmacological equivalents. These salts can be made according to commonorganic techniques employing commercially available reagents. Someanionic salt forms include acetate, acistrate, besylate, bromide,chloride, citrate, fumarate, glucouronate, hydrobromide, hydrochloride,hydroiodide, iodide, lactate, maleate, mesylate, nitrate, pamoate,phosphate, succinate, sulfate, tartrate, tosylate, and xinofoate. Somecationic salt forms include ammonium, aluminum, benzathine, bismuth,calcium, choline, diethylamine, diethanolamine, lithium, magnesium,meglumine, 4-phenylcyclohexylamine, piperazine, potassium, sodium,tromethamine, and zinc.

Some compounds of the invention may exist in stereoisomeric forms, oneexample of which is shown below. The invention includes allstereoisomeric and tautomeric forms of the compounds.

The invention is intended to include all isotopes of atoms occurring inthe present compounds. Isotopes include those atoms having the sameatomic number but different mass numbers. By way of general example andwithout limitation, isotopes of hydrogen include deuterium and tritium.Isotopes of carbon include ¹³C and ¹⁴C. Isotopically-labeled compoundsof the invention can generally be prepared by conventional techniquesknown to those skilled in the art or by processes analogous to thosedescribed herein, using an appropriate isotopically-labeled reagent inplace of the non-labeled reagent otherwise employed. Such compounds mayhave a variety of potential uses, for example as standards and reagentsin determining biological activity. In the case of stable isotopes, suchcompounds may have the potential to favorably modify biological,pharmacological, or pharmacokinetic properties.

Synthetic Methods

The compounds may be made by methods known in the art including thosedescribed below and including variations within the skill of the art.Some reagents and intermediates are known in the art. Other reagents andintermediates can be made by methods known in the art using readilyavailable materials. The following methods are for illustrative purposesand are not intended to limit the scope of the invention. It will beappreciated by those skilled in the art that there are a number ofmethods available for the synthesis of these compounds and that theirsynthesis is not limited to the methods provided in the followingexamples. Variations of the compounds and the procedures to make themwhich are not illustrated are within the skill of the art. The variablesdescribing general structural formulas and features in the syntheticschemes are distinct from and should not be confused with the variablesin the claims or the rest of the specification. These variables aremeant only to illustrate how to make some of the compounds of theinvention.

Abbreviations used in the schemes generally follow conventions used inthe art. Chemical abbreviations used in the specification and examplesare defined as follows: “NaHMDS” for sodium bis(trimethylsilyl)amide;“DMF” for N,N-dimethylformamide; “MeOH” for methanol; “NBS” forN-bromosuccinimide; “TFA” for trifluoroacetic acid; “LAH” for lithiumaluminum hydride; “BOC”, “DMSO” for dimethylsulfoxide; “h” for hours;“rt” for room temperature or retention time (context will dictate);“min” for minutes; “EtOAc” for ethyl acetate; “THF” for tetrahydrofuran;“EDTA” for ethylenediaminetetraacetic acid; “Et₂O” for diethyl ether;“DMAP” for 4-dimethylaminopyridine; “DCE” for 1,2-dichloroethane; “ACN”for acetonitrile; “DME” for 1,2-dimethoxyethane; “HOBt” for1-hydroxybenzotriazole hydrate; “DIEA” for diisopropylethylamine, “Nf”for CF₃(CF₂)₃SO₂—; and “TMOF” for trimethylorthoformate.

Some Formula I compounds can be synthesized through the followinggeneral schemes. Previous known structure II could be arylated withvarious aryl bromide to generated III. III could be deprotected andfurther processed to keto analogs of formula I. The ketone group of IIIcould be alpha-hydroxylated to VII, which could be further converted tohydroxylketone and diol derivatives of formula I. Alternatively, theketone group of III could be reduced to the alcohol IV, which could beeither directly converted to hydroxyl analogs of formula I, or convertedto halogenated analogs V. V could be converted to halogenatedintermediates V. Through azide intermediates VI, various azide, aminederivatives could be prepared. The ketone group of the previously knownII could be transposed to ketone intermediates VIII, and various Arylgroups could be added to generate intermediates IX, which could then beconverted to hydroxyl analogs of formula I. Previously known structuresX could be dehydrated and di-hydroxylated to intermediates XI, whichcould be converted to positional OH analogs of formula I.

As shown in Scheme 1, after deprotection of a previously disclosedcompound, intermediate 1 was generated, which under standard couplingconditions, generated two compounds, examples 1 and 2 (the hydroxylgroup was likely generated through auto-oxidation of enol form withresidual oxygen). The ketone groups of 1 and 2 were reduced to generateexamples 3-6 after careful separation, purification andcharacterization.

The stereochemistry of example 4 was proved and its stereospecificsynthesis was achieved by experiments shown in Scheme 2. Simplereduction of the ketone with sodium borohydride produced two compounds,2 and 3. Treatment of the mixture with TBAF at room temperature onlydeprotected the major component 2 to compound 4, which was easilyseparated from 3. Single crystals were obtained for x-ray analysis,where the cis-diol was confirmed. Treatment of 3 with TBAF underelevated temperature generated the trans-diol 5, whose structure wasalso confirmed by x-ray analysis. Diastereoselective reduction of theketone group was achieved, and after acetate protection and TIPSdeprotection, the intermediate 7 could be converted to example 4, whosespectroscopic properties matched that from previous non-stereospecificsynthesis.

As shown in Scheme 3, compound 2 could be converted to the chloride 8 in83% yield by treatment with triphenylphosphine and NCS. The chloride 8could be converted to the azide intermediate 9. Compounds 8 and 9 areboth single stereoisomers and the reactions likely went through doubleinversion at the hydroxyl-bearing carbon center. After deprotection withTBAF, compound 10 was obtained. Then following a standard couplingreaction, example 7 was obtained in good yield. Treatment of the example7 with triphenylphosphine in THF afforded the amino analog, example 8.

Scheme 3a illustrates an alternative synthesis of example 8.

As shown in Scheme 4, a previously known (S)-hydroxyl ketone wasconverted to the chiral epoxide 11 in 4 steps with 50% overall yield.Hydrogenation opened the epoxide to the alcohol 12 in 97% yield. Swernoxidation afforded ketone 13, which reacted with 2,3-difluorophenyllithium to generate the tertiary alcohol 14 in 79% yield with somerecovery of starting material. After deprotection by TBAF, thetrans-diol was converted to the cis-diol 17 under Mitsunobu conditionsthrough an ester intermediate 16. Single crystals of 17 were obtainedand the relative stereochemistry of the cis-diol in 17 was confirmed byx-ray studies. Finally, compound 17 was converted to example 9 understandard coupling conditions in quantitative yield.

Variation of the aryl groups is exemplified in Scheme 5. Intermediate 18was synthesized using previously described conditions. Synthesis ofexamples 10 and 11 were achieved following procedures described forexamples 8 and 4, respectively, which are described in detail in theexperimental section.

As depicted in scheme 6, compound 19 was obtained from the alcohol shownby treatment with Burgess Reagent. Standard di-hydroxylation affordedtwo separable diastereomeric diols, of which the less polar transcompound 20 was converted to the example 12.

As shown in Scheme 7, mono- and bis-methylatedamine analogs were simplymade by treating the amino analog example 8 with formaldehyde andNaBH₃CN.

Treatment of example 2 with hydroxylamine afforded the oxime products asshown in Scheme 8.

The azide group of intermediate 9 could be reduced to amine 21 andprotected with Boc as shown in Scheme 9. After deprotection, the alcoholgroup can react with isocyanates such as 24, which was prepared in onestep from known aniline 26, to afford carbamate intermediate 25. Upondeprotection, example 17 can be obtained.

As shown in Scheme 10, intermediate 23 was converted to 27 throughMitsunobu reaction. The second Mitsunobu reaction reversed the alcoholchiral center to give 28, which after treatment with hydrazine, affordedthe mono-protected diamine 29. Through previously know reactionconditions and reaction with known reagent 30, compound 31 was obtained.Example 18 was obtained after deprotection of the Boc group.

As indicated in Scheme 11, intermediate 23 could also be converted tothe ketone intermediate 32 through Swern oxidation. The ketone wasconverted to the unsaturated ester 33 by Wittig reaction. Intermediate33, after hydrogenation, afforded two separable isomers 34 and 35. Both34 and 35 was hydrolyzed by aqueous LiOH to afford the intermediateacids 36 and 37, respectively. After standard coupling conditions,intermediate 36 and 37 were converted to examples 19 and 20,respectively. Example 20 was converted to example 21 by treatment withTFA.

Biological Methods In Vitro Pharmacology. Tissue Culture.

SK-N-MC cells were grown at 37° C. in 5% CO₂ as a monolayer in mediumconsisting of MEM with Earle's salts and L-glutamine (Invitrogen)supplemented with 10% fetal bovine serum (Invitrogen).

Membrane Preparation.

Crude membranes were prepared from SK-N-MC cells expressing CGRPreceptors. The cells were rinsed twice with phosphate-buffered saline(155 mM NaCl, 3.3 mM Na₂HPO₄, 1.1 mM KHYDROGENPO₄, pH 7.4), andincubated for 5-10 min. at 4° C. in hypotonic lysis buffer consisting of10 mM Tris (pH 7.4) and 5 mM EDTA. The cells were transferred fromplates to polypropylene tubes (16×100 mm) and homogenized using apolytron. Homogenates were centrifuged at 32,000×g for 30 min. Thepellets were resuspended in cold hypotonic lysis buffer with 0.1%mammalian protease inhibitor cocktail (Sigma) and assayed for proteinconcentration. The SK-N-MC homogenate was aliquoted and stored at −80°C.

Radioligand Binding Assay.

The compounds of invention were solubilized and carried through serialdilutions using 100% DMSO. Aliquots from the compound serial dilutionswere further diluted 25 fold into assay buffer (50 mM Tris-Cl pH 7.5, 5mM MgCl₂, 0.005% Triton X-100) and transferred (volume 50 μl) into 96well assay plates. [¹²⁵I]-CGRP (GE Healthcare or Perkin-Elmer) wasdiluted to 72 pM in assay buffer and a volume of 50 μl was added to eachwell. SK-N-MC membranes were thawed, diluted in assay buffer with fresh0.1% mammalian protease inhibitor cocktail (Sigma), and re-homogenized.SK-N-MC homogenate (7 μg/well) was added in a volume of 100 μl. Theassay plates were then incubated at room temperature for 2 h. Assayswere stopped by addition of excess cold wash buffer (50 mM Tris-Cl pH7.5, 0.1% BSA) immediately followed by filtration over glass fiberfilters (Whatman GF/B) previously soaked in 0.5% PEI. Non-specificbinding was defined with 1 μM beta-CGRP (Bachem). Protein boundradioactivity was determined using a gamma or scintillation counter. Theresulting data was analyzed using a four parameter competitive bindingequation (XLfit v2.0) and the 10₅₀ was defined as the concentration of acompound of invention required to displace 50% of radioligand binding.Final assay concentration of [¹²⁵I]-CGRP was 18 pM. The mean Kd for[¹²⁵I]-CGRP is 25.4 pM. All compounds of invention were evaluated in atleast two separate experiments. See table 1 for data summary.

TABLE 1 Human CGRP Binding Human CGRP Receptor IC₅₀ Example (nM) 1 410 228 3 500 4 0.16 5 1.3 6 8.6 7 0.13 8 0.04 9 na 10 0.20 11 0.89 12 12 130.19 14 2.0 15 28 16 40 17 1.2 18 0.80 19 na 20 na 21 >1000

Pharmaceutical Compositions and Methods of Treatment

The compounds of Formula I inhibit the CGRP receptor. As such, they areuseful for treating conditions or disorders associated with aberrantCGRP levels or where modulating CGRP levels may have therapeuticbenefit.

Accordingly, another aspect of the invention is a pharmaceuticalcomposition comprising a compound of Formula I with a pharmaceuticallyacceptable adjuvant, carrier, or diluent.

Compounds are generally given as pharmaceutical compositions comprisedof a therapeutically effective amount of a compound of Formula I, or apharmaceutically acceptable salt, and a pharmaceutically acceptablecarrier and may contain conventional exipients. A therapeuticallyeffective amount is the amount needed to provide a meaningful patientbenefit as determined by practitioners in that art. Pharmaceuticallyacceptable carriers are those conventionally known carriers havingacceptable safety profiles. Compositions encompass all common solid andliquid forms including capsules, tablets, losenges, and powders as wellas liquid suspensions, syrups, elixers, and solutions. Solidcompositions may by formed in timed or sustained released formulations.Compositions are made using common formulation techniques andconventional excipients (such as binding and wetting agents) andvehicles (such as water and alcohols).

Solid compositions are normally formulated in dosage units providingfrom about 1 to about 1000 mg of the active ingredient per dose. Someexamples of solid dosage units are 0.1 mg, 1 mg, 10 mg, 100 mg, 500 mg,and 1000 mg. Liquid compositions are generally in a unit dosage range of1-100 mg/mL. Some examples of liquid dosage units are 0.1 mg/mL, 1mg/mL, 10 mg/mL, 25 mg/mL, 50 mg/mL, and 100 mg/mL.

The invention encompasses all conventional modes of administrationincluding oral, parenteral, intranasal, sublingual, and transdermalmethods. Typically, the daily dose will be 0.01-100 mg/kg body weightdaily. Generally, more compound is required orally and lessparenterally. The specific dosing regime, however, should be determinedby a physician using sound medical judgement.

Inhibitors at the receptor level to CGRP are postulated to be useful inpathophysiologic conditions where excessive CGRP receptor activation hasoccurred. Some of these include neurogenic vasodilation, neurogenicinflammation, migraine, cluster headache and other headaches, thermalinjury, circulatory shock, menopausal flushing, and asthma. CGRPreceptor activation has been implicated in the pathogenesis of migraineheadache (Edvinsson L. CNS Drugs 2001, 15(10),745-53; Williamson, D. J.Microsc. Res. Tech. 2001, 53, 167-178.; Grant, A. D. Brit. J. Pharmacol.2002, 135, 356-362.). Serum levels of CGRP are elevated during migraine(Goadsby P. J. et al. Ann. Neurol. 1990, 28, 183-7) and treatment withanti-migraine drugs returns CGRP levels to normal coincident withalleviation of headache (Gallai V. et al. Cephalalgia 1995, 15, 384-90).Migraineurs exhibit elevated basal CGRP levels compared to controls(Ashina M. et al., Pain 2000, 86(1-2), 133-8). Intravenous CGRP infusionproduces lasting headache in migraineurs (Lassen L. H. et al.Cephalalgia. 2002, 22(1), 54-61). Preclinical studies in dog and ratreport that systemic CGRP blockade with the peptide antagonist CGRP(8-37) does not alter resting systemic hemodynamics nor regional bloodflow (Shen, Y-T. et al. J. Pharmacol. Exp. Ther. 2001, 298, 551-8).Thus, CGRP-receptor antagonists may present a novel treatment formigraine that avoids the cardiovascular liabilities of activevasoconstriction associated with non-selective 5-HT1B/1D agonists,“triptans” (e.g., sumatriptan).

Another aspect of the invention is a method of inhibiting the CGRPreceptor comprising contacting the CGRP receptor with a compound offormula I or a pharmaceutically acceptable salt thereof.

Another aspect of the invention is a method for treating conditionsassociated with aberrant levels of CGRP comprising the administration ofa therapeutically effective amount of a compound of formula Ito apatient.

Another aspect of the invention is the use of a compound of formula I inthe manufacture of a medicament for the treatment of conditions relatedto aberrant levels of CGRP.

Another aspect of the invention is a method of treating migraine orheadache.

Another aspect of the invention relates to a method of treatinginflammation (particularly neurogenic inflammation), pain, thermalinjury, circulatory shock, diabetes, Reynaud's syndrome, peripheralarterial insufficiency, subarachnoid/cranial hemorrhage, tumor growth,flushing associated with menopause and other conditions the treatment ofwhich can be effected by the antagonism of the CGRP receptor by theadministration of pharmaceutical compositions comprising compounds ofFormula (I) as defined herein.

Another aspect of the invention relates to methods selected from thegroup consisting of (a) immune regulation in gut mucosa (b) protectiveeffect against cardiac anaphylactic injury (c) stimulating or preventinginterleukin-1b(IL-1b)-stimulation of bone resorption (d) modulatingexpression of NK1 receptors in spinal neurons and (e) airwayinflammatory diseases and chronic obstructive pulmonary diseaseincluding asthma. See (a) Calcitonin Receptor-Like Receptor Is Expressedon Gastrointestinal Immune Cells. Hagner, Stefanie; Knauer, Jens;Haberberger, Rainer; Goeke, Burkhard; Voigt, Karlheinz; McGregor, GerardPatrick. Institute of Physiology, Philipps University, Marburg, Germany.Digestion (2002), 66(4), 197-203; (b) Protective effects of calcitoningene-related peptide-mediated evodiamine on guinea-pig cardiacanaphylaxis. Rang, Wei-Qing; Du, Yan-Hua; Hu, Chang-Ping; Ye, Feng; Tan,Gui-Shan; Deng, Han-Wu; Li, Yuan-Jian. School of PharmaceuticalSciences, Department of Pharmacology, Central South University, Xiang-YaRoad 88, Changsha, Hunan, Naunyn-Schmiedeberg's Archives of Pharmacology(2003), 367(3), 306-311; (c) The experimental study on the effectcalcitonin gene-related peptide on bone resorption mediated byinterleukin-1. Lian, Kai; Du, Jingyuan; Rao, Zhenyu; Luo, Huaican.Department of Orthopedics, Xiehe Hospital, Tongji Medical College,Huazhong University of Science and Technology, Wuhan, Peop. Rep. China.Journal of Tongji Medical University (2001), 21(4), 304-307, (d)Calcitonin gene-related Peptide regulates expression of neurokinin1receptors by rat spinal neurons. Seybold V S, McCarson K E, MermelsteinP G, Groth R D, Abrahams L G. J. Neurosci. 2003 23 (5): 1816-1824.epartment of Neuroscience, University of Minnesota, Minneapolis, Minn.55455, and Department of Pharmacology, Toxicology, and Therapeutics,University of Kansas Medical Center, Kansas City, Kans. 66160 (e)Attenuation of antigen-induced airway hyperresponsiveness inCGRP-deficient mice. Aoki-Nagase, Tomoko; Nagase, Takahide; Oh-Hashi,Yoshio; Shindo, Takayuki; Kurihara, Yukiko; Yamaguchi, Yasuhiro;Yamamoto, Hiroshi; Tomita, Tetsuji; Ohga, Eijiro; Nagai, Ryozo;Kurihara, Hiroki; Ouchi, Yasuyoshi. Department of Geriatric Medicine,Graduate School of Medicine, University of Tokyo, Tokyo, Japan. AmericanJournal of Physiology (2002), 283(5,Pt. 1), L963-L970; (f) Calcitoningene-related peptide as inflammatory mediator. Springer, Jochen;Geppetti, Pierangelo; Fischer, Axel; Groneberg, David A. ChariteCampus-Virchow, Department of Pediatric Pneumology and Immunology,Division of Allergy Research, Humboldt-University Berlin, Berlin,Germany. Pulmonary Pharmacology & Therapeutics (2003), 16(3), 121-130;and (g) Pharmacological targets for the inhibition of neurogenicinflammation. Helyes, Zsuzsanna; Pinter, Erika; Nemeth, Jozsef;Szolcsanyi, Janos. Department of Pharmacology and Pharmacotherapy,Faculty of Medicine, University of Pecs, Pecs, Hung. Current MedicinalChemistry: Anti-Inflammatory & Anti-Allergy Agents (2003), 2(2),191-218.

Another aspect of this invention relates to a method of treatment usingcombinations of Formula I compounds with one or more agents selectedfrom the group consisting of COX-2 inhibitors, NSAIDS, aspirin,acetaminophen, triptans, ergotamine and caffeine for the treatment ofmigraine.

“Migraine,” “headache,” and related terms are as understood by medicalpractitioners. Migraine encompasses all classes of migraine includingcommon, classic, cluster, fulgurating, hemiplegic, opthalmoplegic, andopthomalmic.

“Therapeutically effective” means there is a meaningful patient benefitas understood by medical practitioners.

“Patient” means a person who may benefit from treatment as determined bymedical practitioners.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Abbreviations generally follow conventions used in the art. Chemicalabbreviations used in the specification and Examples are defined asfollows: “NaHMDS” for sodium bis(trimethylsilyl)amide; “DMFE” forN,N-dimethylformamide; “MeOH” for methanol; “NBS” forN-bromosuccinimide; “TFA” for trifluoroacetic acid; “LAH” for lithiumaluminum hydride; “BOC”, “DMSO” for dimethylsulfoxide; “h” for hours;“rt” for room temperature or retention time (context will dictate);“min” for minutes; “EtOAc” for ethyl acetate; “THF” for tetrahydrofuran;“EDTA” for ethylenediaminetetraacetic acid; “Et₂O” for diethyl ether;“DMAP” for 4-dimethylaminopyridine; “DCE” for 1,2-dichloroethane; “ACN”for acetonitrile; “DME” for 1,2-dimethoxyethane; “HOBt” for1-hydroxybenzotriazole hydrate; “DIEA” for diisopropylethylamine, “Nf”for CF₃(CF₂)₃SO₂—; and “TMOF” for trimethylorthoformate.

Abbreviations as used herein, are defined as follows: “1×” for once,“2×” for twice, “3 x” for thrice, “° C.” for degrees Celsius, “eq” forequivalent or equivalents, “g” for gram or grams, “mg” for milligram ormilligrams, “L” for liter or liters, “mL” or “ml” for milliliter ormilliliters, “μL” for microliter or microliters, “N” for normal, “M” formolar, “mmol” for millimole or millimoles, “min” for minute or minutes,“h” for hour or hours, “rt” for room temperature, “RT” for retentiontime, “atm” for atmosphere, “psi” for pounds per square inch, “conc.”for concentrate, “sat” or “sat'd “for saturated, “MW” for molecularweight, “mp” for melting point, “ee” for enantiomeric excess, “MS” or“Mass Spec” for mass spectrometry, “ESI” for electrospray ionizationmass spectroscopy, “HR” for high resolution, “HRMS” for high resolutionmass spectrometry, “LCMS” for liquid chromatography mass spectrometry,“HPLC” for high pressure liquid chromatography, “RP HPLC” for reversephase HPLC, “TLC” or “tlc” for thin layer chromatography, “NMR” fornuclear magnetic resonance spectroscopy, “¹H” for proton, “δ” for delta,“s” for singlet, “d” for doublet, “t” for triplet, “q” for quartet, “m”for multiplet, “br” for broad, “Hz” for hertz, and “α”, “β”, “R”, “S”,“E”, and “Z” are stereochemical designations familiar to one skilled inthe art.

Proton magnetic resonance (1H NMR) spectra were recorded on a Bruker AC300 or AC 500. All spectra were determined in the solvents indicated andchemical shifts are reported in δ units downfield from the internalstandard tetramethylsilane (TMS) and interproton coupling constants arereported in Hertz (Hz). Splitting patterns are designated as follows: s,singlet; d, doublet; t, triplet; q, quartet; m, multiplet; br, broadpeak. Low resolution mass spectra (MS) and the apparent molecular (MH+)or (M−H)+ was determined on a Micromass platform. Elemental analyses arereported as percent by weight. The products were purified by Prep HPLCusing the column YMC S5 ODS (30×100 mm) at a flow rate of 40 0 mL/minand gradient time of 8.0 min. starting from solvent composition of 40%methanol-60% water-0.1% TFA and ending with solvent composition 95%methanol-5% water-0.1% TFA. The products were analyzed by a HPLCinstrument using an XTERA column (3.0×50 mm S7) starting from solvent A(10% methanol-90% water-0.1% trifluoroacetic acid (TFA)) and reachingsolvent B (10% water-90% methanol-0.1% TFA) over a gradient time of 2min. The flow rate is 5 mL/min. and retention time (Rf) of product wasmeasured at 220 nm wavelength.

Intermediate 1

(6S,9R)-6-(2,3-Difluorophenyl)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-one

In a 250 mL round-bottom flask was dissolved(9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-one(0.218 g, 0.49 mmol) in tetrahydrofuran (5 mL) to give a colorlesssolution. After cooling to −15° C. (ice-methanol bath) under nitrogen,TBAF (0.490 mL, 0.490 mmol) was added, and the resulting bright yellowsolution was stirred at −15° C. for 1 h (12:00 pm). It was quenched withsodium bicarbonate solution and diluted with ethyl acetate. The layerswere separated and the aqueous layer was extracted with ethyl acetate.The combined organic layers was washed with brine, dried andconcentrated to give a tan oil. FCC (25 g silica gel column) up to 100%ethyl acetate/hexane afforded the desired product (112 mg, 62%). ¹H NMR(400 MHz, CHLOROFORM-d) δ ppm 8.53 (dd, J=4.91, 1.64 Hz, 1H) 7.85 (dd,J=7.68, 1.64 Hz, 1H) 7.34 (dd, J=7.68, 4.91 Hz, 1H) 7.00-7.16 (m, 3H)5.32 (s, 1H) 4.94-5.04 (m, 1H) 4.48 (dd, J=11.83, 3.02 Hz, 1H) 2.14-2.48(m, 4H); 19F NMR (376 MHz, CHLOROFORM-d) δ ppm −138.24-−138.07 (m, 1F)−140.70-−140.50 (m, 1F).

Example 1, 2

(6R,9R)-6-(2,3-Difluorophenyl)-6-hydroxy-5-oxo-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate(example 1) and(9R)-6-(2,3-difluorophenyl)-5-oxo-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate(example 2)

In an oven-dried 100 mL round-bottom flask,(6S,9R)-6-(2,3-difluorophenyl)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-one(112.45 mg, 0.389 mmol) (azeotroped with dry benzene) and 4-nitrophenyl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(224 mg, 0.583 mmol) was suspended in dimethylformamide (3 mL). Aftercooling to −15° C. (ice-methanol bath), NaHMDS (1.555 mL, 1.555 mmol)was added dropwise (10:30 am). The resulting yellow solution was stirredunder nitrogen at −15° C. for 1 h (warmed up to −10° C., turned to deepred solution/suspension). After another 30 min (warmed to −5° C.), thereaction was quenched with sodium bicarbonate solution and diluted withethyl acetate. The layers were separated and the aqueous layer wasextracted with ethyl acetate twice. The combined organic layers werewashed with brine, dried with sodium sulfate, and concentrated to give ayellow oil. Purification by FCC up to 10% methanol/methylene chlorideafforded the desired product (example 2, 60 mg, 29%, a mixture ofdiastereomers) as well as an oxidized product (example 1, 25.5 mg, 12%,a single diastereomer), both as white solids.

Example 2: MS (ESI)[M+H⁺]=534.40; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm11.35 (br. s., 1H) 8.76 (br. s., 1H) 8.00-8.17 (m, 1H) 7.88-8.00 (m, 1H)7.29-7.55 (m, 2H) 6.82-7.19 (m, 4H) 6.20 (br. s., 1H) 4.58 (br. s., 1H)4.24-4.51 (m, 2H) 4.12 (q, J=7.22 Hz, 1H) 2.75-3.17 (m, 2H) 2.02-2.68(m, 6H) 1.89 (br. s., 2H).

Example 1: MS (ESI)[M+H⁺]=550.43; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm10.77 (br. s., 1H) 8.72 (br. s., 1H) 8.06 (d, J=5.04 Hz, 1H) 7.75-7.88(m, 1H) 7.32-7.53 (m, 3H) 7.07-7.23 (m, 2H) 6.99 (br. s., 1H) 6.22 (br.s., 1H) 4.40 (br. s., 4H) 2.94 (d, J=17.88 Hz, 2H) 2.66 (t, J=14.35 Hz,2H) 2.10-2.52 (m, 4H) 1.89 (d, J=11.33 Hz, 2H); 19F NMR (376 MHz,CHLOROFORM-d) δ ppm −135.79-−135.42 (m, 1F) −138.22 (d, J=18.96 Hz, 1F).

Example 3

(5S,6R,9R)-6-(2,3-difluorophenyl)-5,6-dihydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate

In a 100 mL round-bottom flask was dissolved(6R,9R)-6-(2,3-difluorophenyl)-6-hydroxy-5-oxo-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(example 1, 25.5 mg, 0.046 mmol) in methanol (1 mL) to give a colorlesssolution. Sodium borohydride (3.51 mg, 0.093 mmol) was added, and themixture was stirred at room temperature for 30 min. LCMS indicatedcomplete conversion to a more polar compound. The mixture wasconcentrated and directly purified by prep-HPLC. Saturated sodiumbicarbonate was added to basify the solution and the volatile componentswere removed under high vacuum. The remaining solids were repeatedlywashed with methylene chloride and filtered. The solution wasconcentrated to give a white solid (12.2 mg, 45%). The compound was asingle diastereomer, but the relative stereochemistry was notestablished. MS (ESI)[M+H⁺]=552.44; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm10.36 (br. s., 1H) 8.49-8.61 (m, 1H) 8.05 (d, J=5.04 Hz, 1H) 7.71 (d,J=7.30 Hz, 1H) 7.31-7.50 (m, 2H) 7.24-7.30 (m, 1H) 6.91-7.18 (m, 3H)6.14 (br. s., 1H) 4.96 (br. s., 1H) 4.56 (br. s., 1H) 4.41 (br. s., 2H)3.71-3.94 (m, 1H) 2.98 (br. s., 2H) 2.50 (br. s., 1H) 2.33 (br. s., 3H)1.90 (br. s., 5H); 19F NMR (376 MHz, CHLOROFORM-d) δ ppm −135.86,−138.16.

Example 4, 5, 6

(5S,6S,9R)-6-(2,3-difluorophenyl)-5-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate(example 4);(5R,6S,9R)-6-(2,3-difluorophenyl)-5-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H′-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate(example 5); and(5S,6R,9R)-6-(2,3-difluorophenyl)-5-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate

In a 100 mL round-bottom flask was dissolved(9R)-6-(2,3-difluorophenyl)-5-oxo-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(44.4 mg, 0.083 mmol) (example 2) in methanol (1 mL) to give a colorlesssolution. Sodium borohydride (6.30 mg, 0.166 mmol) was added, and themixture was stirred at room temperature for 30 min. LCMS indicatedcomplete conversion to three components (presumably diastereomers), allwith desired MW (M+H=536). The mixture was concentrated and directlypurified by prep-HPLC (0.1% TFA-methanol-water system) to afford threecompounds (order of elution: example 4>5>6, only pure fractionscollected). Direct concentration (acidic solution) under high vacuumgave some decomposition (by LCMS and NMRs). They were individuallytreated with sodium bicarbonate and concentrated to dryness. Theresidues were repeatedly washed with methylene chloride to obtain theindividual free bases. They were then individually purified by FCC (agradient up to 10% methanol/methylene chloride) to afford the productsexample 4 (6.7 mg, 14%), example 5 (5.5 mg, 12%), and example 6 (3.0 mg,6%) as white solids. The relative stereochemistry was not strictlyassigned.

Example 4: 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 10.21 (br. s., 1H) 8.52(d, J=3.53 Hz, 1H) 7.97-8.16 (m, 2H) 7.47 (br. s., 1H) 7.27-7.37 (m, 1H)6.90-7.22 (m, 4H) 5.97 (d, J=10.32 Hz, 1H) 5.32 (d, J=10.4 Hz, 1H)4.26-4.74 (m, 3H) 2.55-3.29 (m, 3H) 2.18-2.49 (m, 4H) 2.07-2.17 (m, 1H)1.59-2.02 (m, 4H); 19F NMR (376 MHz, CHLOROFORM-d) δ ppm −137.26-−136.84(m, 1F) −142.46-−142.13 (m, 1F).

Example 5: 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 10.04 (br. s., 1H) 8.60(dd, J=4.78, 1.26 Hz, 1H) 8.05 (br. s., 1H) 7.66 (d, J=6.55 Hz, 1H) 7.31(dd, J=7.43, 4.91 Hz, 3H) 7.03-7.17 (m, 2H) 6.91-7.03 (m, 1H) 6.25 (d,J=5.79 Hz, 1H) 4.80 (d, J=8.56 Hz, 1H) 4.18-4.66 (m, 3H) 3.38-3.58 (m,2H) 3.02 (d, J=6.29 Hz, 2H) 2.68 (d, J=13.60 Hz, 2H) 2.05-2.45 (m, 3H)1.93 (br. s., 3H);19F NMR (376 MHz, CHLOROFORM-d) δ ppm −138.28 (m, 1F)143.94 (m, 1F).

Example 6: 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 9.47 (br. s., 1H) 8.50(dd, J=4.78, 1.26 Hz, 1H) 8.03 (dd, J=5.16, 1.13 Hz, 1H) 7.35-7.55 (m,3H) 7.04-7.15 (m, 3H) 7.00 (dd, J=7.55, 5.29 Hz, 1H) 6.58 (br. s., 1H)4.85 (s, 1H) 4.61 (br. s., 3H) 3.36 (br. s., 1H) 2.55-3.15 (m, 3H) 2.35(br. s., 1H) 1.83-2.04 (m, 3H) 1.57-1.80 (m, 4H); 19F NMR (376 MHz,CHLOROFORM-d) δ ppm −138.49 (br. s., 1F) −144.30 (m, 1F).

Intermediates 2, 3

(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-oland(5R,6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ol

In a 100 mL round-bottom flask was dissolved(9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-one(510 mg, 1.144 mmol) (mainly trans isomer) in methanol (5 mL) to give acolorless solution. Sodium borohydride (87 mg, 2.29 mmol) was added, andthe mixture was stirred at room temperature for 1 h. LCMS indicatedcomplete conversion. Methanol was removed in vacuo and the residue waspartitioned between water and ethyl acetate. The layers were separated.The organic layer was washed with brine, dried, and concentrated to givea light yellow oil (492 mg, 96%).

Intermediate 4

(5S,6S,9R)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-5,9-diol

In a 100 mL round-bottom flask was dissolved(9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ol(mixture of intermediates 2 and 3, 224.3 mg, 0.501 mmol) intetrahydrofuran (4 mL) to give a colorless solution. TBAF (0.752 mL,0.752 mmol) was added, and the mixture was stirred at room temperaturefor 2 h. LCMS indicated complete conversion of major component while theminor one did not change. Tetrahydrofuran was removed in vacuo and theresidue was partitioned between water and ethyl acetate. The layers wereseparated and the aqueous layer was extracted with ethyl acetate. Thecombined organic layer was washed with brine, dried with Sodium sulfate,and concentrated to give a tan oil. FCC up to 50% ethyl acetate/hexaneafforded intermediate 3 unchanged (38 mg, 17%) as a white crystallinesolid, and intermediate 4 (95 mg, 65%) as a colorless oil (solidifiedupon standing). Intermediate 4 was further crystallized and singlecrystals were obtained. Its relative stereochemistry was proven by x-raystudies.

Intermediate 3: MS (ESI)[M+H⁺]=448.43; 1H NMR (400 MHz, CHLOROFORM-d) δppm 8.34-8.48 (m, 1H) 7.62 (d, J=7.55 Hz, 1H) 7.15 (dd, J=7.81, 4.78 Hz,1H) 6.89-7.05 (m, 1H) 6.67-6.82 (m, 1H) 6.24 (br. s., 1H) 5.81 (br. s.,1H) 5.38 (d, J=4.78 Hz, 1H) 3.93 (br. s., 1H) 2.59 (br. s., 1H) 2.31 (d,J=4.53 Hz, 1H) 2.13-2.25 (m, 1H) 2.01-2.12 (m, J=14.20, 7.07, 7.07, 3.65Hz, 1H) 1.85-2.01 (m, 1H) 1.10-1.23 (m, 3H) 1.02-1.08 (m, 9H) 0.93-1.00(m, 9H).

Intermediate 4: MS (ESI)[M+H⁺]=292.26; 1H NMR (400 MHz, CHLOROFORM-d) δppm 8.45 (dd, J=4.78, 1.26 Hz, 1H) 8.10 (d, J=7.81 Hz, 1H) 7.24-7.36 (m,1H) 6.97-7.18 (m, 3H) 5.77-6.44 (m, 1H) 5.08 (d, J=10.07 Hz, 1H)4.70-4.84 (m, 1H) 2.93-3.08 (m, 1H) 2.55 (br. s., 1H) 2.17-2.38 (m, 2H)2.04-2.13 (m, 1H) 1.39-1.58 (m, 1H); 19F NMR (376 MHz, CHLOROFORM-d) δppm −137.35-−136.88 (m, 1F) −142.50-−142.13 (m, 1F); 13C NMR (101 MHz,CHLOROFORM-d) δ ppm 157.58 (s, 1C) 150.05-152.35 (dd, J=12.5 and 199 Hz,1C) 147.63-149.87 (dd, J=13.0 and 197 Hz, 1C) 145.43 (s, 1C) 136.62 (s,1C) 133.15 (s, 1C) 132.69 (d, J=11.56 Hz, 1C) 124.36-124.79 (m, 1C)123.71 (br. s., 1C) 122.74 (s, 1C) 115.75 (d, J=16.96 Hz, 1C) 71.37 (s,1C) 71.12 (s, 1C) 46.21 (br. s., 1C) 35.70 (s, 1C) 32.83 (s, 1C).

Intermediate 5

((5R,6S,9R)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-5,9-diol

In a 100 mL round-bottom flask was dissolved(5R,6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ol(91 mg, 0.203 mmol) (intermediate 3) in tetrahydrofuran (2 mL) to give acolorless solution. TBAF (0.407 mL, 0.407 mmol) was added, and themixture was heated at 50° C. overnight for 16 h. LCMS showed completeconversion. The mixture was diluted with ethyl acetate and water. Thelayers were separated and the aqueous layer was extracted with ethylacetate. The combined organic layers were washed with brine, dried withsodium sulfate, and concentrated to give a tan oil. FCC up to 50% ethylacetate/hexane afforded the desired product (55.5 mg, 94%) as a whitecrystalline solid. Intermediate 5 was further crystallized and singlecrystals were obtained. Its relative stereochemistry was established byx-ray studies. MS (ESI)[M+H⁺]=292.26; 1H NMR (400 MHz, CHLOROFORM-d) δppm 8.37 (dd, J=5.04, 1.51 Hz, 1H) 7.52 (dd, J=7.55, 1.51 Hz, 1H)7.37-7.49 (m, 1H) 7.19 (dd, J=7.30, 5.04 Hz, 1H) 7.00-7.15 (m, 2H) 5.96(br. s., 1H) 5.23 (dd, J=11.58, 2.27 Hz, 1H) 4.78 (s, 1H) 3.22-3.32 (m,1H) 3.10 (br. s., 1H) 2.74-2.89 (m, 1H) 2.29 (dddd, J=13.60, 5.16, 2.77,2.64 Hz, 1H) 1.77-1.91 (m, 1H) 1.47-1.67 (m, 1H); 19F NMR (376 MHz,CHLOROFORM-d) δ ppm −138.73-−138.11 (m, 1F) −144.45-−144.03 (m, 1F); 13CNMR (101 MHz, CHLOROFORM-d) δ ppm 160.75 (s, 1C) 149.14-151.82 (dd,J=14.0 and 246 Hz, 1C) 146.49-149.15 (dd, J=12.0 and 244 Hz, 1C) 146.14(s, 1C) 136.75 (s, 1C) 135.45 (s, 1C) 134.93 (d, J=10.79 Hz, 1C)123.79-124.30 (m, 1C) 123.38 (s, 1C) 122.20 (s, 1C) 115.24 (d, J=16.96Hz, 1C) 77.94 (s, 1C) 70.62 (s, 1C) 40.42 (s, 1C) 36.62 (s, 1C) 26.81(s, 1C).

Intermediate 6

(5S6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylacetate

In a 250 mL round-bottom flask was dissolved(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ol(1.004 g, 2.243 mmol) in methylene chloride (20 mL) to give a colorlesssolution. Acetic anhydride (0.423 mL, 4.49 mmol) and triethylamine(0.938 mL, 6.73 mmol) were added, followed by DMAP (0.055 g, 0.449mmol). The mixture was stirred at room temperature under nitrogen. 2 h:LCMS showed complete conversion. It was quenched with Sodium bicarbonatesolution and diluted with ethyl acetate. The layers were separated. Theorganic layer was washed with brine, dried and concentrated to give acolorless oil (100%), which was directly carried onto next reactionwithout further purification and characterization. MS(ESI)[M+H⁺]=490.26.

Intermediate 7

(5S,6S,9R)-6-(2,3-difluorophenyl)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylacetate

In a 100 mL round-bottom flask was dissolved(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylacetate (1098 mg, 2.243 mmol) (azeotroped with dry benzene) intetrahydrofuran (20 mL) to give a colorless solution. TBAF (2.69 mL,2.69 mmol) was added, and the resulting light yellow solution wasstirred at room temperature for 2 h (8:30 am). LCMS indicated completeconversion. Tetrahydrofuran was removed in vacuo and the residue wasdiluted with water and ethyl acetate. The layers were separated. Theorganic layer was washed with brine, dried, and concentrated to give acolorless oil. Purification by FCC up to 70% ethyl acetate/hexaneafforded the desired product (648 mg, 87% for 2 steps) as a colorlessoil. MS (ESI)[M+H⁺]=334.21; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.47(dd, J=4.78, 1.51 Hz, 1H) 7.69 (d, J=7.30 Hz, 1H) 7.28 (dd, J=7.81, 5.04Hz, 1H) 6.94-7.10 (m, 3H) 6.20 (d, J=10.32 Hz, 1H) 5.95 (br. s., 1H)4.95 (dd, J=11.21, 1.64 Hz, 1H) 3.16-3.31 (m, 1H) 2.27-2.41 (m, 2H)2.06-2.19 (m, 1H) 1.80 (s, 3H) 1.48-1.63 (m, 1H); 13C NMR (101 MHz,CHLOROFORM-d) δ ppm 168.96 (s, 1C) 157.96 (s, 1C) 149.66-151.75 (d,J=12.6 and 199 Hz, 1C) 147.21-149.29 (d, J=13 and 198 Hz, 1C) 146.00 (s,2C) 133.43 (s, 1C) 132.23 (d, J=11.56 Hz, 1C) 131.99 (s, 2C)123.90-124.24 (m, 2C) 122.89 (br. s., 1C) 122.66 (s, 2C) 115.36 (d,J=16.95 Hz, 2C) 72.77 (s, 2C) 71.14 (s, 3C) 42.12 (br. s., 1C) 35.66 (s,2C) 32.68 (s, 2C) 20.28 (s, 2C); 19F NMR (376 MHz, CHLOROFORM-d) δ ppm−138.20-−137.93 (m, 1F) −143.38-−143.16 (m, 1F).

Example 4

(5S,6S,9R)-6-(2,3-difluorophenyl)-5-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate(example 4)

In an oven-dried 100 mL round-bottom flask was suspended(5S,6S,9R)-6-(2,3-difluorophenyl)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylacetate (96.7 mg, 0.290 mmol) (azeotroped with dry benzene) and4-nitrophenyl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(167 mg, 0.435 mmol) in dimethylformamide (3 mL) under nitrogen. Aftercooling to −15° C. (ice-methanol bath), NaHMDS (0.870 mL, 0.870 mmol)was added dropwise. The resulting dark-red solution was stirred undernitrogen at −15° C.˜0° C. for 1 h. LCMS showed desired product andpossible over-hydrolysed product. After another 1 h at room temperature,complete hydrolysis was not yet achieved. The reaction was quenched withsodium bicarbonate solution and volatiles were removed. The mixture wasdiluted with ethyl acetate. The layers were separated and the aqueouslayer was extracted twice with ethyl acetate. The combined organiclayers were washed with brine, dried with sodium sulfate, andconcentrated to give a yellow oil. Purification by FCC up to 10%methanol/methylene chloride afforded the acetate-protected product (2ndpeak, 51 mg, 30%, not pure) as well as the target alcohol (3rd peak, 20mg, 13%). In a 250 mL round-bottom flask was(5S,6S,9R)-5-acetoxy-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(51 mg, 0.088 mmol) (acetate protected product from above) in methanol(1 mL) to give a colorless solution. Potassium carbonate (122 mg, 0.883mmol) was added, and the mixture was stirred at room temperature for 1h. LCMS indicated complete conversion. Methanol was removed in vacuo.The residue was partitioned between water and ethyl acetate. The layerswere separated (no product in aqueous layer by LCMS). The organic layerwas washed with brine, dried, and concentrated to give a white solid.Purification by FCC up to 10% methanol/methylene chloride afforded thedesire product (28 mg, 56%) as a light yellow solid. 1H and 19F NMRspectra were obtained and matched that of example 4.

Intermediate 8

(5R,6S,9R)-5-chloro-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine

In an oven-dried 250 mL round-bottom flask was suspended NCS (0.751 g,5.62 mmol) in tetrahydrofuran (15 mL). Triphenylphosphine (1.475 g, 5.62mmol) was added. After stirring under nitrogen for 5 min,(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ol(1.007 g, 2.250 mmol) was added in one portion to the gray suspension.The resulting reddish suspension was stirred at room temperature. Thesolids gradually dissolved to give a tan solution. After 5 h, LCMSindicated complete conversion. Tetrahydrofuran was removed in vacuo andthe remaining red oil was directly purified by ISCO (240 g silicacolumn) up to 60% ethyl acetate/hexane. Pure ethyl acetate eluted thenon polar component and the product was eluted by 10% methanol (with2.0M NH₄OH) in Methylene chloride. The product fractions were combinedand re-purified by FCC up to 50% Ethyl acetate/hexane to afford thedesired product as a colorless oil (869 mg, 83%). MS (ESI)[M+H⁺]=466.22;1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.55 (d, J=3.53 Hz, 1H) 7.63 (br.s., 1H) 7.20 (dd, J=7.68, 4.91 Hz, 1H) 7.01-7.15 (m, 1H) 6.90-7.01 (m,1H) 6.66-6.90 (m, 1H) 5.55-5.85 (m, 1H) 5.40-5.56 (m, 1H) 3.96-4.33 (m,1H) 2.33 (br. s., 3H) 2.09-2.20 (m, 1H) 1.14-1.23 (m, 3H) 1.04-1.14 (m,9H) 1.01 (d, J=7.30 Hz, 9H).

Intermediate 9

(5S6S,9R)-5-azido-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine

In a 100 mL round-bottom flask was dissolved(5R,6S,9R)-5-chloro-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine(566 mg, 1.214 mmol) in dimethylformamide (5 mL) to give a colorlesssolution. Sodium azide (474 mg, 7.29 mmol) was added, and the mixturewas stirred at room temperature under nitrogen for 2.5 h. LCMS indicatedonly partial reaction. The mixture was heated at 50° C. overnight. After15 h, LCMS indicated complete conversion with some elimination product.The mixture was diluted with water and ethyl acetate. The layers wereseparated. The organic layer was washed with brine, dried, andconcentrated to give a colorless oil. The crude product was carried ontothe next reaction without further purification and characterization.Smaller scale purification afforded an analytical sample: MS(ESI)[M+H⁺]=473.27; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.52-8.63 (m,1H) 7.75 (d, J=7.81 Hz, 1H) 7.23-7.36 (m, 1H) 6.95-7.17 (m, 2H) 6.89(br. s., 1H) 5.28 (d, J=4.03 Hz, 1H) 4.90 (d, J=9.07 Hz, 1H) 3.79 (t,J=9.44 Hz, 1H) 1.86-2.23 (m, 4H) 1.16-1.30 (m, 3H) 0.98-1.15 (m, 18H);19F NMR (376 MHz, CHLOROFORM-d) δ ppm −137.68-−137.36 (m, 1F)−141.78-−141.54 (m, 1F).

Intermediate 10

(5S6S,9R)-5-azido-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-ol

In a 100 mL round-bottom flask was dissolved(5S,6S,9R)-5-azido-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine(0.732 g, 1.549 mmol) (crude) in tetrahydrofuran (8 mL) to give acolorless solution. TBAF (1.859 mL, 1.859 mmol) was added, and theresulting light yellow solution was stirred at room temperature for 1.5h. LCMS indicated complete conversion. Tetrahydrofuran was removed andthe residue was diluted with water and ethyl acetate. The layers wereseparated. The organic layer was washed with brine, dried, andconcentrated to give a light yellow oil. Purification by FCC up to 60%ethyl acetate/hexane afforded the desired product (crude weight: 480 mg)as a colorless oil. Smaller scale purification afforded an analyticalsample: MS (ESI)[M+H⁺]=317.22; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.51(dd, J=4.91, 1.38 Hz, 1H) 7.99 (d, J=7.30 Hz, 1H) 7.35 (dd, J=7.81, 5.04Hz, 1H) 7.06-7.20 (m, 2H) 6.94-7.05 (m, 1H) 5.91 (br. s., 1H) 5.03 (d,J=10.32 Hz, 1H) 4.92 (dd, J=11.21, 2.39 Hz, 1H) 2.84-3.02 (m, 1H)2.37-2.49 (m, 1H) 2.25-2.36 (m, 1H) 2.07-2.17 (m, J=14.38, 4.94, 3.05,3.05 Hz, 1H) 1.40-1.64 (m, 1H); 13C NMR (101 MHz, CHLOROFORM-d) δ ppm158.48 (s, 1C) 152.19-149.87 (dd, J=13.10 and 221 Hz, 1C) 149.72-147.42(dd, J=13.87 and 219 Hz, 1C) 146.16 (s, 3C) 133.67 (s, 2C) 133.23 (s,1C) 132.66 (d, J=10.79 Hz, 1C) 124.43 (dd, J=6.94, 3.85 Hz, 2C) 123.84(br. s., 1C) 122.89 (s, 2C) 115.98 (d, J=17.73 Hz, 2C) 70.94 (s, 3C)65.67 (s, 1C) 45.43 (br. s., 1C) 35.71 (s, 3C) 33.45 (s, 2C); 19F NMR(376 MHz, CHLOROFORM-d) δ ppm −137.55-−137.20 (m, 1F) −142.28-−141.89(m, 1F).

Example 7

(5S,6S,9R)-5-azido-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate

In a 100 mL round-bottom flask was dissolved(5S,6S,9R)-5-azido-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-ol(0.490 g, 1.549 mmol) (azeotroped with dry benzene) and 4-nitrophenyl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(0.713 g, 1.859 mmol) in dimethylformamide (8 mL) to give a light yellowsuspension under nitrogen. After cooling to −15° C. (ice-methanol bath),NaHMDS (4.18 mL, 4.18 mmol) was added dropwise. The resulting tansolution was stirred under nitrogen at −10° C.˜0° C. for 2 h and at roomtemperature for 2 h. LCMS showed complete conversion. The reaction wasquenched with sodium bicarbonate solution. The mixture was diluted withethyl acetate. The layers were separated and the aqueous layer wasextracted with ethyl acetate. The combined organic layers were washedwith water, brine, dried with sodium sulfate, and concentrated to give atan oil. Purification by FCC up to 8% methanol/methylene chlorideafforded the desired prodcut (major peak, 632 mg, 73% for 3 steps) as alight yellow foam. MS (ESI)[M+H⁺]=561.27; 1H NMR (400 MHz, CHLOROFORM-d)δ ppm 11.50 (br. s., 1H) 8.58 (d, J=3.78 Hz, 1H) 8.11 (d, J=5.04 Hz, 1H)7.91 (d, J=7.30 Hz, 1H) 7.33 (br. s., 2H) 7.07-7.19 (m, 2H) 6.92-7.06(m, 2H) 6.10 (d, J=9.32 Hz, 1H) 5.23 (d, J=10.07 Hz, 1H) 4.26-4.84 (m,3H) 2.46-3.34 (m, 4H) 2.20-2.43 (m, 3H) 2.01-2.13 (m, 1H) 1.94 (d,J=12.34 Hz, 3H); 19F NMR (376 MHz, CHLOROFORM-d) δ ppm −137.30-−137.01(m, 1F) −142.32-−142.03 (m, 1F).

Example 8

(5S6S,9R)-5-amino-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate

In a 100 mL round-bottom flask was dissolved(5S,6S,9R)-5-azido-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(620 mg, 1.106 mmol) (example 7) in tetrahydrofuran (5 mL) to give acolorless solution. Trimethylphosphine (3.32 mL, 3.32 mmol, 1.0 M intoluene) was added. The mixture was stirred at room temperature. After 2h, LCMS showed no starting material. Water (0.080 mL, 4.42 mmol) wasadded, and the mixture was stirred for another 3 h. LCMS showed completeconversion to the desired product. Volatile components were removed invacuo and the residue was directly purified by FCC up to 10% methanol inmethylene chloride to afford the product (510 mg, 85%) as a white solid.MS (ESI)[M+H⁺]=535.23; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 10.39 (br.s., 1H) 8.52 (d, J=3.78 Hz, 1H) 8.09 (d, J=5.04 Hz, 2H) 7.46 (br. s.,1H) 7.26-7.38 (m, 1H) 7.06-7.20 (m, 3H) 6.94-7.05 (m, 1H) 6.06-6.23 (m,1H) 4.31-4.78 (m, 4H) 4.05 (spt, J=6.13 Hz, 1H) 2.57-3.25 (m, 3H)2.17-2.38 (m, 3H) 1.42-2.04 (m, 6H); 19F NMR (376 MHz, CHLOROFORM-d) δppm −136.90 (br. s., 1F) −142.48-−142.21 (m, 1F).

Intermediate 11

Epoxide.

1. In an oven-dried 250 mL round-bottom flask was dissolved5(S)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-one (3.16 g,17.83 mmol) in Methylene chloride (50 mL) to give a tan solution. Aftercooling to 0° C., TIPS-OTf (4.84 mL, 17.83 mmol) and triethylamine (4.97mL, 35 7 mmol) were added via syringe, and the mixture was stirred at 0°C. for 1 h. LCMS indicated complete conversion. Volatile components wereremoved in vacuo and the residue partitioned between sodium bicarbonatesolution and ethyl acetate. The layers were separated and the organiclayer was washed with brine, dried and concentrated to give a tan oil.The crude product was directly used in the next reaction. MS(ESI)[M+H⁺]=334.28.

2. In a 250 mL round-bottom flask was dissolved(S)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-one(5.95 g, 17.83 mmol) (crude) in methanol (50 mL) to give a tan solution.Sodium borohydride (0.675 g, 17.83 mmol) was added, and the mixture wasstirred at room temperature for 1 h. LCMS indicated complete conversion.Methanol was removed in vacuo and the residue was partitioned betweenwater and ethyl acetate. The layers were separated. The organic layerwas washed with brine, dried with sodium sulfate, and concentrated togive a tan oil, which was carried onto next reaction without furtherpurification and characterization. MS (ESI)[M+H⁺]=336.28 (LCMS showedtwo diastereomers).

3. In a 250 mL round-bottom flask wassuspended(9S)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ol(5.98 g, 17.83 mmol) and (methoxycarbonylsulfamoyl)triethylammoniumhydroxide, inner salt (6.37 g, 26.7 mmol) in benzene (100 mL). Themixture was heated at reflux (preheated oil bath at 85° C.) withstirring under nitrogen for 5 h. LCMS showed complete conversion.Volatile components were removed in vacuo and the residue waspartitioned between water and ethyl acetate. The layers were separated.The organic layer was washed with brine, dried and concentrated to givea tan oil (6.3 g), which was directly used in the next reaction withoutfurther purification and characterization. MS (ESI)[M+H⁺]=318.32.

4. In a 2 L round-bottom flask was added sodium hypochlorite (658 mL,574 mmol). Sodium phosphate (bibasic) (3.04 g, 21.40 mmol) was added.After cooling to 0° C.,(S,Z)-9-(triisopropylsilyloxy)-8,9-dihydro-7H-cyclohepta[b]pyridine(5.66 g, 17.83 mmol) (crude) and manganese(III)6,6′-(1E,1′E)-(1R,2R)-cyclohexane-1,2-diylbis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(2,4-di-tert-butylphenolate)chloride (1.359 g, 2.140 mmol) dissolved in methylene chloride (140 mL)was added dropwise over 1 h. The dark reaction mixture was allowed toslowly warm to room temperature and stirred overnight for 20 h. LCMSshowed product peak with no starting material. The mixture was dilutedwith water and ether. The layers were separated and the aqueous layerwas extracted with ether twice. The combined organic layers were washedwith water, brine, dried with celite, filtered, and concentrated to givea dark oil. Purification by FCC up to 50% ethyl acetate/hexane affordedthe desired product as a light yellow oil (2.98 g, 50% for 4 steps). 1HNMR (400 MHz, CHLOROFORM-d) δ ppm 8.25-8.44 (m, 1H) 7.81 (d, J=8.31 Hz,1H) 7.13 (td, J=7.05, 3.53 Hz, 1H) 4.94-5.16 (m, 1H) 3.88-4.04 (m, 1H)3.25-3.48 (m, 1H) 2.18-2.38 (m, 1H) 1.89-2.11 (m, 2H) 1.11-1.29 (m, 1H)0.62-1.10 (m, 21H).

Intermediate 12

(6S,9S)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-6-ol

In a 500 mL round-bottom flask was dissolved intermediate 11 (2.98 g,8.93 mmol) in methanol (60 mL) to give a yellow solution. Pd/C (10%,0.475 g, 0.447 mmol) was added. The mixture was stirred under hydrogen(1 atm) at room temperature for 2 h. LCMS showed good conversion. Afteranother 1 h, the mixture was filtered and washed with methanol. Thecombined organic solution was concentrated to give a light yellow oil,and further dried over 3 days to give a light yellow solid (2.91 g,97%), which was used in the next step without further purification andcharacterization. MS (ESI)[M+H⁺]=336.35.

Intermediate 13

(S)-9-(triisopropylsilyloxy)-8,9-dihydro-5H-cyclohepta[b]pyridin-6(7H)-one

In an oven-dried 250 mL round-bottom flask was dissolved oxalyl chloride(9.54 mL, 19.08 mmol) in methylene chloride (40 mL) to give a colorlesssolution at −55° C. under nitrogen. DMSO (2.71 mL, 38 2 mmol) was addeddropwise slowly over 2 min. After the solution was stirred for anadditional 30 min,(6S,9S)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-6-ol(2.91 g, 8.67 mmol) (crude, azeotroped with dry benzene) dissolved in 8mL methylene chloride (plus 8 mL rinse) was added via canuula over 5min. The reaction mixture was stirred at −50 to −55° C. for anadditional 40 min. Triethylamine (6.04 mL, 43 4 mmol) was added viasyringe at −50° C. and the reaction mixture was gradually warmed up to−20° C. for 30 min. TLC showed complete conversion. Water and ethylacetate were added, and the layers were separated. The aqueous layer wasextracted with ethyl acetate. The combined organic layers were driedwith sodium sulfate, and concentrated to give a tan oil. Purification byFCC up to 50% ethyl acetate/hexane afforded the desired product as alight yellow oil (2.08 g, 72%). MS (ESI)[M+H⁺]=334.35; 1H NMR (400 MHz,CHLOROFORM-d) δ ppm 8.39 (d, J=5.04 Hz, 1H) 7.49 (d, J=7.55 Hz, 1H) 7.19(dd, J=7.55, 4.78 Hz, 1H) 5.26 (dd, J=4.78, 2.27 Hz, 1H) 4.69 (d,J=14.35 Hz, 1H) 3.29 (d, J=14.35 Hz, 1H) 3.02 (ddd, J=12.15, 9.00, 6.04Hz, 1H) 2.45-2.59 (m, 1H) 2.31-2.45 (m, 1H) 2.06-2.25 (m, J=8.53, 8.53,5.98, 2.39 Hz, 1H) 1.06-1.19 (m, 3H) 1.01 (d, J=7.30 Hz, 9H) 0.89-0.97(m, 9H).

Intermediate 14

(6S,9S)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-6-ol

In an oven-dried 250 mL round-bottom flask was dissolved1,2-difluorobenzene (0.680 mL, 6.90 mmol) in tetrahydrofuran (12 mL)under nitrogen. After cooling to −65° C., n-BuLi (1M in hexanes, 2.208mL, 5.52 mmol) was added dropwise via syringe. After the mixture wasstirred between −65 and −60° C. for 30 min, it was cooled down to −78°C. A solution of(S)-9-(triisopropylsilyloxy)-8,9-dihydro-5H-cyclohepta[b]pyridin-6(7H)-one(920.5 mg, 2.76 mmol) (80304-043) in tetrahydrofuran (4 mL plus 4 mLrinse) was added via syringe (turned to yellow) and the reaction wasstirred at −78° C. for 1 h (yellow color), and at room temperature for30 min (red color). LCMS indicated good conversion. The reaction wasquenched by saturated NH₄Cl solution. Tetrahydrofuran was removed andthe residue was partitioned between water and ethyl acetate. The layerswere separated. The organic layer was washed with brine, dried withsodium sulfate, and concentrated to give a tan oil. Purification by FCCup to 80% ethyl acetate/hexane afforded the recovered SM (197 mg, 21%)as a yellow oil as well as the desired products (977 mg, 79%) as acolorless oil. MS (ESI)[M+H⁺]=448.33; 1H NMR (400 MHz, CHLOROFORM-d) δppm 8.26 (d, J=3.53 Hz, 1H) 7.42 (t, J=6.42 Hz, 1H) 7.35 (d, J=7.30 Hz,1H) 6.99-7.13 (m, 3H) 5.16 (br. s., 1H) 4.63 (d, J=13.85 Hz, 1H)3.02-3.28 (m, 1H) 2.71 (d, J=14.10 Hz, 1H) 2.34 (d, J=4.03 Hz, 1H)2.02-2.15 (m, 2H) 1.75 (d, J=13.85 Hz, 1H) 1.06-1.19 (m, J=14.67, 7.27,7.27, 7.05 Hz, 3H) 0.97-1.07 (m, 9H) 0.84-0.97 (m, 9H).

Intermediate 15

(6S,9S)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-6,9-diol

In a 250 mL round-bottom flask was dissolved(6R,95)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-6-ol(977 mg, 2.183 mmol) in tetrahydrofuran (10 mL) to give a colorlesssolution. TBAF (4.80 mL, 4.80 mmol) was added, and the mixture wasstirred at 50° C. overnight for 16 h. LCMS indicated good conversionwith some SM left. Another 0.2 equiv of TBAF was added and the reactioncontinued at 50° C. for 2 h. Tetrahydrofuran was removed and the residuewas partitioned between water and ethyl acetate. The layers wereseparated and the aqueous layer was extracted with ethyl acetate. Thecombined organic layers were washed with brine, dried with sodiumsulfate, and concentrated to give a tan oil. Purification by FCC up to10% methanol/methylene chloride afforded the desired product as a whitesolid (458 mg, 72%). MS (ESI)[M+H⁺]=292.21; 1H NMR (400 MHz,CHLOROFORM-d) δ ppm 8.05 (d, J=3.78 Hz, 1H) 7.37 (d, J=7.55 Hz, 1H)7.06-7.21 (m, 1H) 6.81-7.05 (m, 3H) 5.63 (br. s., 1H) 4.82-4.97 (m, 1H)3.68-4.11 (m, 2H) 3.00 (d, J=14.35 Hz, 1H) 2.77 (t, J=10.58 Hz, 1H) 2.13(t, J=11.21 Hz, 1H) 1.87-2.03 (m, 1H) 1.69-1.86 (m, 1H); 19F NMR (376MHz, CHLOROFORM-d) δ ppm −137.37 (br. s., 1F) −137.99 (d, J=15.52 Hz,1F).

Intermediate 16

(6S,9R)-6-(2,3-difluorophenyl)-6-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-nitrobenzoate

In a 250 mL round-bottom flask was dissolved(6S,9S)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-6,9-diol(458 mg, 1.572 mmol) (azeotroped with dry benzene) in tetrahydrofuran (8mL) to give a light orange solution. 4-Nitrobenzoic acid (394 mg, 2.358mmol) and triphenylphosphine (619 mg, 2.358 mmol) were added undernitrogen. Diisopropyl azodicarboxylate (0.464 mL, 2.358 mmol) was addeddropwise. The mixture was allowed to stir overnight. After 15 h, LCMSshowed complete conversion, but the desired product was a minorcomponent. It was concentrated to a light yellow oil and directlypurified by FCC (5% ethyl acetate/hexanes to 100%) to afford the desiredproduct (125 mg, 18%) as a white solid. MS (ESI)[M+H⁺]=441.20.

Intermediate 17

(6S,9R)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-6,9-diol

In a 250 mL round-bottom flask was dissolved(6S,9R)-6-(2,3-difluorophenyl)-6-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-nitrobenzoate (125 mg, 0.284 mmol) in tetrahydrofuran (2 mL) to give acolorless solution. Lithium hydroxide (0.568 mmol) was added, and themixture was stirred at room temperature for 2 h. LCMS indicated completeconversion. It was diluted with ethyl acetate and water. The layers wereseparated and the aqueous layer was extracted with ethyl acetate. Thecombined organic layers were washed with brine, dried, and concentratedto a white solid. Purification by FCC up to 6% methanol/methylenechloride afforded the desired product as a white crystalline solid (71mg, 86%). A few crystals were picked out and an x-ray structure wasobtained to confirm the cis-diol stereochemistry. MS (ESI)[M+H⁺]=292.21;1H NMR (500 MHz, CHLOROFORM-d) δ ppm 8.44 (d, J=4.58 Hz, 1H) 7.38-7.51(m, 2H) 7.19 (dd, J=7.48, 5.04 Hz, 1H) 7.04-7.16 (m, 2H) 5.99 (br. s.,1H) 4.90 (dd, J=11.29, 2.14 Hz, 1H) 3.80-3.91 (m, 1H) 2.92 (dd, J=14.65,2.14 Hz, 1H) 2.57-2.70 (m, 1H) 2.37 (br. s., 1H) 2.11 (ddd, J=14.19,5.95, 3.97 Hz, 1H) 1.96-2.06 (m, 1H) 1.74-1.91 (m, 1H); 19F NMR (470MHz, CHLOROFORM-d) δ ppm −138.91-−138.74 (m, 1F) −139.22-−139.06 (m,1F); 13C NMR (126 MHz, CHLOROFORM-d) δ ppm 160.64 (s, 1C) 152.00-150.10(dd, J=21.42 and 254.52 Hz, 1C) 148.75-146.71 (dd, J=11.52 and 244.44Hz, 1C) 145.55 (s, 3C) 139.91 (s, 3C) 138.44 (d, J=8.64 Hz, 1C) 129.37(s, 1C) 123.89-124.57 (m, 2C) 122.48 (s, 3C) 120.84 (s, 1C) 116.22 (d,J=17.28 Hz, 2C) 71.79 (m, 3C) 71.70 (m, 4C) 44.30 (d, J=4.80 Hz, 2C)39.65 (s, 1C) 31.29 (s, 2C).

Example 9

(6S,9R)-6-(2,3-difluorophenyl)-6-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate

In an oven-dried 100 mL round-bottom flask was dissolved(6S,9R)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-6,9-diol(71 mg, 0.244 mmol) (azeotroped with dry benzene) and 4-nitrophenyl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(121 mg, 0.317 mmol) in dimethylformamide (2 mL) to give a light yellowsuspension under nitrogen. NaHMDS (0.926 mL, 0.926 mmol) was addeddropwise. The resulting yellow suspension was stirred under nitrogen atroom temperature for 3.5 h. LCMS showed complete conversion. Thereaction was quenched with saturated sodium bicarbonate and diluted withethyl acetate. The layers were separated and the aqueous layer wasextracted with ethyl acetate (LCMS showed no product left in the aqueousphase). The combined organic layers were washed with water, brine, driedwith sodium sulfate, and concentrated to give a yellow oil. Purificationby FCC up to 10% methanol/methylene chloride afforded the desiredproduct (131 mg, 100%) as a white powder. LCMS and HPLC showed >99%purity. MS (ESI)[M+H⁺]=536.26; 1H NMR (500 MHz, CHLOROFORM-d) δ ppm11.31 (br. s., 1H) 8.35-8.50 (m, 1H) 7.97-8.11 (m, 1H) 7.31-7.60 (m, 3H)7.02-7.18 (m, 3H) 6.98 (dd, J=7.48, 5.34 Hz, 1H) 6.03 (d, J=10.68 Hz,1H) 4.60 (br. s., 2H) 4.40 (br. s., 1H) 3.97 (d, J=14.34 Hz, 1H)2.80-3.20 (m, 4H) 2.67 (t, J=11.75 Hz, 2H) 2.17-2.40 (m, 2H) 2.08 (t,J=12.67 Hz, 2H) 1.89 (d, J=11.29 Hz, 2H); 19F NMR (470 MHz,CHLOROFORM-d) δ ppm −138.72 (d, J=15.15 Hz, 2F).

Intermediate 18

(5S,6S,9R)-6-(3,5-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ol

1. A mixture of sodium 2-methylpropan-2-olate (0.827 g, 8.61 mmol),diacetoxypalladium (0.057 g, 0.255 mmol),dicyclohexyl(2′-methylbiphenyl-2-yl)phosphine (0.093 g, 0.255 mmol),(R)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-one(2.1264 g, 6.38 mmol) and 1-bromo-3,5-difluorobenzene (0.881 mL, 7.65mmol) was heated at 80° C. in toluene (24 mL, degassed before use)) for18 h under nitrogen. The solvent was mostly removed via vacuum and thereaction was diluted with ethyl acetate. The ethyl acetate layer waswashed with water three times before drying (sodium sulfate), filteredand concentrated. Flash chromatography using ethyl acetate in hexane (0to 35% to 50%) gave the desired arylation product (51%). HPLC t_(R)=3.55min,

MS (ESI)[M+H⁺]=446.26, 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.64 (dd,J=4.91, 1.64 Hz, 1H) 7.89-7.95 (m, 1H) 7.37-7.43 (m, 1H) 6.65-6.75 (m,3H) 5.29-5.35 (m, 1H) 4.40-4.46 (m, 1H) 2.30-2.37 (m, 2H) 2.04-2.16 (m,2H) 1.02-1.11 (m, 3H) 0.95-1.02 (m, 9H) 0.93 (d, J=7.30 Hz, 9H); 19F NMR(376 MHz, CHLOROFORM-d) δ ppm −109.94-−109.73 (s), 111.37 (s).

2. Lithium borohydride (0.283 g, 13.01 mmol) was added to a cyclopentylmethyl ether (15 mL) solution of(6S,9R)-6-(3,5-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-one(1.4496 g, 3.25 mmol) at 0° C. under nitrogen. The reaction was stirredat 0° C. for 6 h at room temperature. The reaction was quenched byadding methanol and continued to stir for 0.5 h. The solvent was removedvia vacuum and the crude residue was taken up in ethyl acetate, whichwas washed by water three times. Flash chromatography using ethylacetate in hexane from 0 to 10% gave the desired product (56%). HPLCt_(R)=3.05 min,

MS (ESI)[M+H⁺]=448.26; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.44 (dd,J=4.91, 1.64 Hz, 1H) 7.46 (dd, J=7.55, 1.51 Hz, 1H) 7.15 (dd, J=7.55,5.04 Hz, 1H) 6.50-6.61 (m, 1H) 6.41 (dd, J=8.94, 1.89 Hz, 2H) 5.69-5.83(m, 1H) 5.21-5.30 (m, 1H) 4.62-4.80 (m, 1H) 3.46-3.64 (m, 1H) 2.84-3.09(m, 1H) 2.06-2.24 (m, 2H) 1.79-1.97 (m, 1H) 1.12-1.34 (m, 3H) 1.04-1.10(m, 9H) 1.01 (d, J=7.30 Hz, 9H); 19F NMR (376 MHz, CHLOROFORM-d) δ ppm−109.90 (t, J=8.62 Hz, 2F).

Example 10

(5S6S,9R)-5-amino-6-(3,5-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate

1. In an oven-dried 100 mL round-bottom flask was suspended NCS (324 mg,2.423 mmol) in tetrahydrofuran (4 mL). Triphenylphosphine (636 mg, 2.423mmol) was added in one portion. After stirring under nitrogen for 5 min,(5S,6S,9R)-6-(3,5-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ol(493 mg, 1.101 mmol) dissolved in 1 mL tetrahydrofuran (1 mL rinse) wasadded via canuula to the gray suspension. The resulting grayishsuspension was stirred at room temperature. After 5 h, LCMS indicatedlittle conversion. The reaction was continued at 40° C. overnight for 16h. LCMS showed complete conversion. The reaction was quenched withSodium bicarbonate solution and diluted with ethyl acetate. The layerswere separated. The organic layer was washed with brine, dried, andconcentrated to give a dark oil. Purification by FCC up to 20% ethylacetate/hexane afforded the desired product (386 mg, 75%, contaminatedwith a closely-moving peak) as a colorless oil, which was used directlyin the next step. The major peak (tR=3.39 min) was the eliminationproduct (MS (ESI)[M+H^(+])=430.30) while the minor peak (t_(R)=3.29 min)is the chloride (MS (ESI)[M+H⁺]=466.22).

2. In a 100 mL round-bottom flask was dissolved(5R,6S,9R)-5-chloro-6-(3,5-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine(386 mg, 0.828 mmol) in dimethylformamide (4 mL) to give a colorlesssolution. Sodium azide (323 mg, 4.97 mmol) was added, and the mixturewas stirred at 50° C. under nitrogen for 20 h. TLC (4/1 hexane/ethylacetate) showed two close peaks (the less polar major component was theelimination product from the starting material and the more polar minorone was the azide product). It was diluted with water and ethyl acetate.The layers were separated. The organic layer was washed with brine,dried, and concentrated to give a colorless oil. Purification by FCC upto 20% ethyl acetate/hexane afforded the desired product (2nd minorpeak) (70 mg, 18%, 13% for 2 steps) as a colorless oil. MS(ESI)[M+H⁺]=473.27; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.59 (dd,J=4.91, 1.64 Hz, 1H) 7.64-7.72 (m, 1H) 7.26-7.36 (m, 1H) 6.64-6.82 (m,3H) 5.27 (t, J=4.41 Hz, 1H) 4.71 (d, J=8.31 Hz, 1H) 3.57-3.71 (m, 1H)2.10 (d, J=4.53 Hz, 3H) 1.72-1.87 (m, 1H) 1.14-1.27 (m, 3H) 0.99-1.12(m, 18H); 19F NMR (376 MHz, CHLOROFORM-d) δ ppm −109.44-−109.27 (m, 2F).

3. In a 100 mL round-bottom flask was dissolved(5S,6S,9R)-5-azido-6-(3,5-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine(70 mg, 0.148 mmol) in tetrahydrofuran (1 mL) to give a colorlesssolution. TBAF (0.178 mL, 0.178 mmol) was added, and the resultedcolorless solution was stirred at room temperature for 1 h. LCMSindicated complete conversion. Tetrahydrofuran was removed in vacuo andthe residue was diluted with water and ethyl acetate. The layers wereseparated. The organic layer was washed with brine, dried, andconcentrated to give a colorless oil. Purification by FCC up to 60%ethyl acetate/hexane afforded the desired product (46.2 mg, 99%) as acolorless oil. MS (ESI)[M+H⁺]=317.22; 1H NMR (400 MHz, CHLOROFORM-d) δppm 8.52 (d, J=3.78 Hz, 1H) 7.99 (d, J=7.81 Hz, 1H) 7.36 (dd, J=7.81,4.78 Hz, 1H) 6.69-6.88 (m, 3H) 5.45-6.32 (m, 1H) 4.91 (dd, J=10.95, 2.39Hz, 1H) 4.84 (d, J=10.32 Hz, 1H) 2.66 (td, J=10.70, 3.53 Hz, 1H)2.07-2.38 (m, 3H) 1.41-1.59 (m, 1H); ¹⁹F NMR (376 MHz, CHLOROFORM-d) δppm −109.08 (t, J=8.62 Hz, 2F); 13C NMR (101 MHz, CHLOROFORM-d) δ ppm163.16 (dd, J=248.93, 13.10 Hz, 1C) 158.31 (s, 1C) 146.84 (t, J=8.48 Hz,1C) 146.24 (s, 2C) 133.88 (s, 2C) 132.76 (s, 1C) 122.92 (s, 2C)110.30-111.00 (m, 2C) 102.68 (t, J=25.43 Hz, 2C) 70.96 (s, 2C) 66.28 (s,2C) 50.08 (s, 1C) 35.24 (s, 2C) 34.74 (s, 2C).

4. In a 100 mL round-bottom flask was suspended(5S,6S,9R)-5-azido-6-(3,5-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-ol(46 mg, 0.145 mmol) (azeotroped with dry benzene) and 4-nitrophenyl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(66.9 mg, 0.175 mmol) in dimethylformamide (1 mL) under nitrogen. Aftercooling to −15° C. (ice-methanol bath), NaHMDS (0.393 mL, 0.393 mmol)was added dropwise. The resulting tan solution was stirred undernitrogen at −10° C. ˜0° C. for 2 h and at room temperature for 2 h. LCMSshowed good conversion. The reaction was quenched with sodiumbicarbonate solution. The mixture was diluted with ethyl acetate. Thelayers were separated and the aqueous layer was extracted with ethylacetate. The combined organic layers were washed with water, brine,dried with sodium sulfate, and concentrated to give a tan oil.Purification by FCC up to 8% methanol/methylene chloride afforded thedesired product (62 mg, 76%) as a white solid. MS (ESI)[M+H⁺]=561.20; 1HNMR (400 MHz, CHLOROFORM-d) δ ppm 11.07 (br. s., 1H) 8.59 (d, J=3.78 Hz,1H) 8.11 (d, J=4.28 Hz, 1H) 7.88 (d, J=6.55 Hz, 1H) 7.24-7.54 (m, 2H)7.01 (dd, J=7.55, 5.29 Hz, 1H) 6.65-6.92 (m, 3H) 6.12 (d, J=7.81 Hz, 1H)5.11 (d, J=9.57 Hz, 1H) 4.28-4.85 (m, 3H) 2.51-3.34 (m, 4H) 2.22-2.43(m, 2H) 2.02-2.24 (m, 2H) 1.77-2.01 (m, 3H); 19F NMR (376 MHz,CHLOROFORM-d) δ ppm −108.89 (t, J=9.4 Hz, 2F).

5. In a 100 mL round-bottom flask was dissolved(5S,6S,9R)-5-azido-6-(3,5-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(62 mg, 0.11 mmol) in tetrahydrofuran (1 mL) to give a colorlesssolution. Trimethylphosphine (0.332 mL, 0.332 mmol) was added. Themixture was stirred at room temperature. After 2 h, water (7.97 μL,0.442 mmol) was added, and the mixture was stirred at room temperatureovernight. LCMS showed complete conversion to the desired product.Volatile components were removed in vacuo and the residue was directlypurified by FCC up to 10% methanol in methylene chloride to afford theproduct as a white solid that was further dried in vacuo over three days(56 mg, 90%).

MS (ESI)[M+H⁺]=535.23; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 11.45 (br.s., 1H) 8.45 (d, J=3.78 Hz, 1H) 8.00 (d, J=4.53 Hz, 2H) 7.16-7.48 (m,2H) 6.92 (dd, J=7.81, 5.29 Hz, 1H) 6.82 (d, J=6.04 Hz, 2H) 6.69 (tt,J=8.81, 2.27 Hz, 1H) 6.07 (dd, J=10.07, 3.27 Hz, 1H) 4.22-4.77 (m, 4H)3.01 (br. s., 2H) 2.58 (d, J=2.52 Hz, 2H) 2.13-2.39 (m, 3H) 1.98-2.11(m, 1H) 1.69-1.97 (m, 5H); 19F NMR (376 MHz, CHLOROFORM-d) δ ppm −108.85(br. s., 2F).

Example 11

(5S6S,9R)-6-(3,5-difluorophenyl)-5-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate

1. To a methylene chloride (10 mL) solution of(5S,6S,9R)-6-(3,5-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ol(0.492 g, 1.099 mmol) under nitrogen was added acetic anhydride (0.207mL, 2.198 mmol), triethylamine (0.460 mL, 3.30 mmol) and DMAP (0.027 g,0.220 mmol) at room temperature. The reaction was stirred for 2 h. Thereaction was diluted with methylene chloride and washed with sodiumcarbonate (sat). The methylene chloride layer was separated, dried(sodium sulfate), filtered and concentrated to give the crude product asa light yellow oil (0.538 g, 100%). HPLC t_(R)=3.19 min, MS(ESI)[M+H⁺]=490.26, 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.56 (dd,J=4.78, 1.51 Hz, 1H) 7.72 (dd, J=7.81, 1.26 Hz, 1H) 7.23 (dd, J=7.81,4.78 Hz, 1H) 6.62-6.76 (m, 3H) 6.19 (d, J=9.07 Hz, 1H) 5.23-5.30 (m, 1H)3.48-3.57 (m, 1H) 3.15-3.18 (m, 1H) 2.08-2.20 (m, 2H) 1.92-1.98 (m, 1H)1.17-1.25 (m, 3H) 1.07-1.14 (m, 9H) 1.04 (d, J=7.30 Hz, 9H); 19F NMR(376 MHz, CHLOROFORM-d) δ ppm −109.71 (t, J=8.62 Hz, 2F).

2. TBAF (1.319 mL, 1.319 mmol) was added to a tetrahydrofuran (6 mL)solution of(5S,6S,9R)-6-(3,5-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylacetate (0.538 g, 1.099 mmol) at room temperature under nitrogen. Thereaction was stirred for 1 h. LCMS showed complete conversion. Thesolvent was removed via vacuum and the crude mixture was partitionedbetween ethyl acetate and brine. The ethyl acetate layer was separated,dried (sodium sulfate), filtered and concentrated. Flash chromatographyusing ethyl acetate in hexane from 0 to 50% gave the desired product(0.2786 g, 75%). (Rf ca. 0.86 in 50% ethyl acetate in hexane). HPLCt_(R)=1.88 min, MS (ESI)[M+H⁺]=334.21, 1H NMR (400 MHz, CHLOROFORM-d) δppm 8.38-8.49 (m, 1H) 7.67 (d, J=7.81 Hz, 1H) 7.26 (dd, J=7.81, 4.78 Hz,1H) 6.60-6.78 (m, 3H) 6.17 (d, J=10.58 Hz, 1H) 5.92 (d, J=3.78 Hz, 1H)4.89 (m, 1H) 2.80 (m, 1H) 2.28-2.13 (m, 3H) 1.80 (s, 3H) 1.47 (m, 1H);19F NMR (376 MHz, CHLOROFORM-d) δ ppm −109.62 (s, 2F); 13C NMR (101 MHz,CHLOROFORM-d) δ ppm 168.94 (s, 1C) 162.82 (dd, J=248.16, 13.10 Hz, 1C)157.96 (s, 1C) 146.98 (t, J=8.86 Hz, 1C) 146.02 (s, 1C) 133.16 (s, 1C)132.08 (s, 1C) 122.64 (s, 1C) 110.44 (d, J=25.43 Hz, 1C) 102.14 (t,J=24.66 Hz, 1C) 72.81 (s, 1C) 71.11 (s, 1C) 49.61 (s, 1C) 35.39 (s, 1C)33.94 (s, 1C) 20.27 (s, 1C).

3. NaHMDS (1.839 mL, 1.839 mmol) was added to a dimethylformamide (4 mL)solution of(5S,6S,9R)-6-(3,5-difluorophenyl)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylacetate (0.2786 g, 0.836 mmol) and 4-nitrophenyl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(0.3337 g, 0.870 mmol) at −20° C. under nitrogen. The reaction wasstirred at −20° C. for 3 h, and then treated with 0.1 eq of4-nitrophenyl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylateand 0.15 mL of NaHMDS. The reaction was stirred for another hour whileit was warmed up to −10° C. LCMS showed the desired product as well asthe hydrolyzed alcohol (loss of acetyl group). The reaction was quenchedwith water, followed by addition of ethyl acetate. The ethyl acetatelayer was washed three times by water before separated, dried (sodiumsulfate), filtered and concentrated to give the crude product. HPLCt_(R)=2.58 min,

MS (ESI)[M+H⁺]=578.26 Potassium carbonate (785 mg, 5.68 mmol) was addedto the methanol (5 mL) solution of(5S,6S,9R)-5-acetoxy-6-(3,5-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(328 mg, 0.568 mmol) at room temperature. The reaction was stirred atroom temperature for 1 h before removal of the solvent. The crude waspartitioned between ethyl acetate and water. The ethyl acetate layer wasseparated and washed again with water before dried (sodium sulfate),filtered and concentrated. Flash chromatography using methanol inmethylene chloride from 0 to 10% gave the desired product (135.3 mg,42%). HPLC t_(R)=2.17 min, MS (ESI)[M+H⁺]=536.26, 1H NMR (400 MHz,CHLOROFORM-d) δ ppm 10.61 (br. s., 1H) 8.52 (d, J=3.78 Hz, 1H) 7.97-8.14(m, 2H) 7.23-7.58 (m, 2H) 7.02 (dd, J=7.81, 5.29 Hz, 1H) 6.80-6.90 (m,2H) 6.75 (tt, J=8.84, 2.23 Hz, 1H) 5.94 (br. s., 1H) 5.15 (d, J=9.57 Hz,1H) 4.31-4.79 (m, 3H) 2.87-3.26 (m, 2H) 2.68-2.80 (m, 1H) 2.03-2.55 (m,5H) 1.76-2.00 (m, 3H); 19F NMR (376 MHz, CHLOROFORM-d) δ ppm −108.58(br. s., 2F).

Intermediate 19

(R,Z)-6-(2,3-difluorophenyl)-6,7-dihydro-5H-cyclohepta[b]pyridine

In an oven-dried 250 mL round-bottom flask was mixed(6R,9R)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-ol(1.93 g, 7.01 mmol) and (methoxycarbonylsulfamoyl)triethylammoniumhydroxide, inner salt (2.005 g, 8.41 mmol) in benzene (60 mL) to give asuspension. It was heated at 85° C. with stirring under nitrogen for 1 h(color quickly changed to deep red). LCMS showed desired MW. TLC (1/1ethyl acetate/hexanes) showed only a trace of SM left and a major, morepolar component. Benzene was removed in vacuo and the residue waspartitioned between ethyl acetate and water. The layers were separatedand the aqueous layer was extracted with ethyl acetate. The combinedorganic layers were washed with brine, dried and concentrated to give atan oil. Purification by FCC up to 80% ethyl acetate/hexane afforded thedesired product (0.81 g, 45%) as a light yellow oil. MS(ESI)[M+H⁺]=258.16, 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.45 (dd,J=4.78, 1.51 Hz, 1H) 7.35 (d, J=7.55 Hz, 1H) 6.92-7.09 (m, 4H) 6.77 (dt,J=12.53, 1.92 Hz, 1H) 6.20 (dt, J=12.59, 4.53 Hz, 1H) 3.43-3.58 (m, 1H)3.22 (dd, J=14.10, 9.57 Hz, 1H) 2.96 (d, J=14.35 Hz, 1H) 2.69 (td,J=5.29, 2.01 Hz, 2H); 13C NMR (101 MHz, CHLOROFORM-d) δ ppm 154.90 (s,1C) 151.94-149.34 (dd, J=13.10 and 249.47 Hz, 1C) 149.43-146.86 (dd,J=12.33 and 247.45 Hz, 1C) 147.31 (s, 2C) 136.93 (s, 2C) 135.63 (d,J=11.56 Hz, 1C) 134.74 (s, 1C) 133.74 (s, 2C) 131.83 (s, 2C)123.95-124.47 (m, 2C) 122.61 (t, J=3.47 Hz, 2C) 121.44 (s, 2C) 115.15(d, J=16.96 Hz, 2C) 40.28 (s, 2C) 38.53 (s, 2C) 37.70 (s, 1C); 19F NMR(376 MHz, CHLOROFORM-d) δ ppm −138.33-−137.90 (m, 1F) −144.07-−143.71(m, 1F).

Intermediate 20

(6S,8R,9S)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-8,9-diol

In a 50 mL round-bottom flask was dissolved(R,Z)-6-(2,3-difluorophenyl)-6,7-dihydro-5H-cyclohepta[b]pyridine (110mg, 0.428 mmol) and NMO (110 mg, 0.941 mmol) in acetone (2 mL) and water(0.04 mL) to give a tan solution. Osmium tetroxide (0.021 mL, 1.710μmol) (2.5 wt-% solution in 2-methyl-2-propanol) was added (the tancolor instantly changed to very light yellow). The mixture was stirredat room temperature. 1 h: <5% conversion. 0.021 mL OsO₄ was added. 22 h:⅓ conversion. Another 0.021 mL OsO₄ solution was added. 28 h (50 htotal). Sodium bisulfate (1.2 g) was added and stirring continued for 30min. Acetone was removed in vacuo and the residue was extracted withethyl acetate three times. The combined organic layers were washed withbrine, dried and concentrated to an off-white solid. FCC (a few drops ofmethanol helped to completely dissolve the solids in methylene chloride)up to 10% methanol/methylene chloride afforded two products: a lesspolar, likely the desired trans product (61 mg, 49%) and a more polarcis product (47.1 mg, 38%) as white solids. MS (ESI)[M+H⁺]=258.16, 1HNMR (400 MHz, CHLOROFORM-d) δ ppm 8.46 (d, J=5.04 Hz, 1H) 7.50 (dd,J=7.55, 1.26 Hz, 1H) 7.22 (dd, J=7.43, 4.91 Hz, 1H) 7.01-7.10 (m, 3H)5.04 (s, 1H) 4.43 (br. s., 1H) 3.35 (dd, J=11.33, 3.53 Hz, 1H) 3.24 (t,J=12.97 Hz, 1H) 2.86 (d, J=14.35 Hz, 1H) 2.30-2.44 (m, 2H); 19F NMR (376MHz, CHLOROFORM-d) δ ppm −138.07-−137.86 (m, 1F) −142.98-−142.63 (m,1F).

Example 12

(6S,8R,9S)-6-(2,3-difluorophenyl)-8-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate

In an oven-dried 100 mL round-bottom flask was dissolved(6S,8R,9S)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-8,9-diol(61 mg, 0.209 mmol) (azeotroped with dry benzene) and1-(1-(1H-imidazole-1-carbonyl)piperidin-4-yl)-1H-imidazo[4,5-b]pyridin-2(3H)-one(65.4 mg, 0.209 mmol) in tetrahydrofuran (2 mL) to give a colorlesssolution under nitrogen. After cooling to 0° C. (ice bath), potassiumt-butoxide (1M in tetrahydrofuran, 0.754 mL, 0.754 mmol) was addeddropwise, and the tan suspension was warmed up to room temperature withstirring. After 2 h some SM remained. Another 20 mg of1-(1-(1H-imidazole-1-carbonyl)piperidin-4-yl)-1H-imidazo[4,5-b]pyridin-2(3H)-onewas added, and the mixture was left stirring overnight. After 18 h thereaction was quenched with sodium bicarbonate solution and diluted withethyl acetate. The layers were separated and the aqueous layer wasextracted with ethyl acetate twice. The combined organic layers werewashed with brine, dried with sodium sulfate, and concentrated to give ayellow oil. Purification by FCC up to 10% methanol/methylene chlorideafforded the desired product (last peak, 16 mg, 14%) as a light yellowfoam. MS (ESI)[M+H⁺]=536.26, 1H NMR (400 MHz, CHLOROFORM-d) δ ppm8.27-8.59 (m, 1H) 8.08 (dd, J=5.29, 1.26 Hz, 1H) 7.54 (d, J=2.52 Hz, 1H)7.31-7.51 (m, 1H) 7.22 (dd, J=7.30, 5.04 Hz, 1H) 6.93-7.19 (m, 4H)5.39-5.63 (m, 1H) 5.18 (br. s., 1H) 4.45-4.64 (m, 1H) 4.37 (br. s., 1H)3.10-3.40 (m, 3H) 2.92 (d, J=13.85 Hz, 1H) 2.11-2.88 (m, 5H) 1.75-1.95(m, 2H) 1.55-1.71 (m, 1H).

Example 13, 14

(5S,6S,9R)-6-(2,3-difluorophenyl)-5-(methylamino)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(example 13) and(5S,6S,9R)-6-(2,3-difluorophenyl)-5-(dimethylamino)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(example 14)

In a 5 mL round-bottom flask was dissolved(5S,6S,9R)-5-amino-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(35.8 mg, 0.067 mmol) (example 8) in methanol (0.5 mL) to give acolorless solution. Formaldehyde (0.025 mL, 0.335 mmol) (36.5% solution)and sodium cyanoborohydride (25.3 mg, 0.402 mmol) were added, and themixture was stirred at room temperature overnight. After 18 h, LCMSshowed complete conversion to two products. The mixture was partitionedbetween ethyl acetate and saturated sodium bicarbonate solution. Thelayer was separated and the aqueous layer was extracted with ethylacetate. The combined organic layers were washed with brine, dried withsodium sulfate, and concentrated to give a dense oil/foam. FCC up to 10%methanol/methylene chloride gave no separation. The products wasseparated by prep-HPLC (ammonium acetate in methanol/water) to affordedexample 13 (14 mg, 34%), and example 14 (25.5 mg, 66%), both ascolorless solids/foams.

Exampe 13: MS (ESI)[M+H⁺]=549.2; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm10.33 (br. s., 1H) 8.47-8.63 (m, 1H) 8.09 (d, J=4.78 Hz, 2H) 7.49 (br.s., 2H) 7.07-7.19 (m, 3H) 7.03 (dd, J=7.81, 5.29 Hz, 1H) 6.23 (d, J=1.01Hz, 1H) 4.38-4.77 (m, 3H) 4.27 (br. s., 1H) 3.01 (br. s., 3H) 2.55-2.84(m, 1H) 2.20-2.45 (m, 6H) 1.74-2.01 (m, 5H); 19F NMR (376 MHz,CHLOROFORM-d) δ ppm −137.02-−136.44 (m, 1F) −142.71-−141.48 (m, 1F).

Example 14: MS (ESI)[M+H⁺]=563.3; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm10.87 (br. s., 1H) 8.58 (d, J=4.28 Hz, 1H) 8.03-8.14 (m, 1H) 7.64-7.95(m, 1H) 7.37-7.52 (m, 1H) 7.28 (s, 1H) 6.93-7.19 (m, 4H) 6.26 (br. s.,1H) 4.60 (br. s., 3H) 3.61-4.04 (m, 2H) 2.86-3.23 (m, 2H) 2.13-2.67 (m,10H) 1.92 (d, J=14.86 Hz, 2H) 1.59 (br. s., 2H); 19F NMR (376 MHz,CHLOROFORM-d) δ ppm −137.79-−137.11 (m, 1F) −143.70-−143.05 (m, 1F).

Example 15, 16

(6S,9R,Z)-6-(2,3-difluorophenyl)-5-(hydroxyimino)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate(example 15) and(6S,9R,E)-6-(2,3-difluorophenyl)-5-(hydroxyimino)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-h]pyridin-1-yl)piperidine-1-carboxylate(example 16)

In a 250 mL round-bottom flask was dissolved(9R)-6-(2,3-difluorophenyl)-5-oxo-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate(217 mg, 0.407 mmol) (example 2) in ethanol (8 mL) to give a colorlesssolution. Hydroxylamine hydrochloride (283 mg, 4.07 mmol) andHunig'sBase (0.852 mL, 4.88 mmol) were added. The mixture was stirred at80° C. under nitrogen for 4 days. Ethanol had evaporated, and a dense,slightly tan oil was left. LCMS showed the desired product and TLC (10%methanol/methylene chloride) showed some degree of conversion. Theresidue was partitioned between water and ethyl acetate. The layers wereseparated and the aqueous layer was extracted with ethyl acetate. Thecombined organic layers were washed with brine, dried with sodiumsulfate, and concentrated to a colorless foam. Careful purification byFCC and prep-HPLC afforded the shown examples 15 and 16: MS(ESI)[M+H⁺]=549.07.

Intermediate 21

(5S6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-amine

A mixture of(5S,6S,9R)-5-azido-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine(598 mg, 1.265 mmol)(intermediate 9) and palladium (10% on activatedcarbon) (0.504 mg, 0.474 μmol) in ethanol (25 ml) was stirred underhydrogen (1 atm) for 2.5 h. LCMS indicated that the desired compound wasformed, stirring was continued. After 5 h, the mixture was filtered,washed thoroughly with ethanol, and then concentrated to give 21 (525mg, 93%) as a colorless oil: MS (ESI)[M+H⁺]=447.3.

Intermediate 22

tert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate

A mixture of(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-amine(660 mg, 1.478 mmol) and di-t-butyl dicarbonate (410 mg, 1.879 mmol) intetrahydrofuran (10 mL) was stirred at room temperature overnight.Propylamine was added, and volatile components were removed in vacuo.The residue was purified with flash column chromatography to afford thedesired product (604 mg, 75%) as colorless sticky syrup: MS(ESI)[M+H⁺]=547.4.

Intermediate 23

tert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate

To a solution of tert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate(600 mg, 1.097 mmol) in tetrahydrofuran (15 mL)N-butyl-N,N-dipropylbutan-1-aminium fluoride (1.207 mL, 1.2067 mmol) wasadded at room temperature. After 1 h, LCMS showed the reaction wascomplete. Aqueous sodium bicarbonate solution was added (5 ml). Thesolvent was removed in vacuo and the mixture was extracted with ethylacetate, dried over sodium sulfate, and concentrated to give a colorlesssolid which was purified with flash column chromatography to give thedesired product (371 mg, 87%): MS (ESI)[M+H⁺]=547.4.

Intermediate 24

5-isocyanato-1,3-dihydrospiro[indene-2,3′-pyrrolo[2,3-h]pyridin]-2′(1′H)-one

To a solution of phosgene (0.150 mL, 0.300 mmol) in methylene chloride(1.5 mL)5-amino-1,3-dihydrospiro[indene-2,3′-pyrrolo[2,3-b]pyridin]-2′(1′H)-one(0.025 g, 0.1 mmol) in methylene chloride (2.00 mL) was added at 0° C.Stirring was continued at room temperature. After 1 h stirring LCMSindicated that SM was consumed and the desired compound was formed (MS(ESI)[M+HOMe⁺]=310.2.). nitrogen gas was bubbled into the mixture, toremove the excess phosgene. The dry residue was co-evaporated once withmethylene chloride, and dried under high vacuum for 1.5 h. The residuewas used directly for next step.

Intermediate 25

(5S,6S,9R)-6-(2,3-difluorophenyl)-5-(tert-butylcarbamoyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl2′-oxo-1,1′,2′,3-tetrahydrospiro[indene-2,3′-pyrrolo[2,3-h]pyridine]-5-ylcarbamate

To a solution of5-isocyanato-1,3-dihydrospiro[indene-2,3′-pyrrolo[2,3-b]pyridin]-2′(1′H)-one(27.5 mg, 0.099 mmol) in Methylene chloride (2.000 ml) a solution oftert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate(35.1 mg, 0.09 mmol) and Hunig's base (0.031 ml, 0.180 mmol) inmethylene chloride (2.00 ml) was added at 0° C. Stirring was continuedat room temperature overnight. The mixture was purified with Prep HPLC(gradient with 30 to 100% methanol in water) to give the desired product(28 mg, 46.6%) as a white amorphous solid: MS (ESI)[M+HOMe⁺]=668.1; ¹HNMR (500 MHz, CDCl₃) δ 9.56 (d, J=6.5 Hz, 1H), 9.39 (d, J=5.2 Hz, 1H),8.49 (d, J=7.4 Hz, 1H), 7.99 (d, J=5.7 Hz, 1H), 7.97-7.88 (m, 1H),7.69-7.33 (m, 4H), 7.25-6.99 (m, 3H), 6.44 (d, J=10.7 Hz, 1H), 5.64-4.96(m, 3H), 4.81 (s, 1H), 3.84-3.64 (m, 2H), 3.25-2.96 (m, 3H), 2.58 (dd,J=46.7, 11.3 Hz, 2H), 2.19 (d, J=11.7 Hz, 1H), 1.95 (d, J=11.5 Hz, 1H),1.38-1.21 (m, 9H).

Example 17

(5S,6S,9R)-5-amino-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl2′-oxo-1,1′,2′,3-tetrahydrospiro[indene-2,3′-pyrrolo[2,3-h]pyridine]-5-ylcarbamate(example 17)

To a solution of(5S,6S,9R)-6-(2,3-difluorophenyl)-5-(tert-butylcarbamoyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl2′-oxo-1,1′,2′,3-tetrahydrospiro[indene-2,3′-pyrrolo[2,3-b]pyridine]-5-ylcarbamate(28 mg, 0.042 mmol) in methylene chloride (1.0 mL) 2,2,2-trifluoroaceticacid (1 mL, 12.98 mmol) was added at 0° C. Stirring was continued atroom temperature for 10 min. LCMS indicated that the Boc group had beenremoved. Stirring was continued for 50 min. The reaction mixture wascoevaporated with toluene, and dried. The residue was purified withPrep. HPLC (gradient w/25 to 100% methanol (0.1% TFA)) to give thedesired product (19.5 mg, 51%, 99% purity by analytical HPLC) as whiteamorphous solid: MS (ESI)[M+H⁺]=568.3; ¹H NMR (500 MHz, MeOD) δ 8.66(dd, J=4.9, 1.3 Hz, 1H), 8.11-8.05 (m, 1H), 7.82 (d, J=7.8 Hz, 1H), 7.56(dd, J=7.9, 4.9 Hz, 1H), 7.50 (s, 1H), 7.40-7.27 (m, 6H), 7.25 (d, J=8.2Hz, 1H), 7.22-7.18 (m, 1H), 6.93 (ddd, J=7.3, 5.4, 1.8 Hz, 1H), 6.26(dd, J=9.1, 4.7 Hz, 1H), 5.25 (d, J=9.6 Hz, 1H), 3.60-3.45 (m, 3H), 3.12(d, J=6.6 Hz, 1H), 3.09 (d, J=6.3 Hz, 1H), 2.38 (dd, J=11.8, 7.0 Hz,1H), 2.22 (d, J=7.4 Hz, 1H), 1.99 (d, J=18.6 Hz, 2H).

Intermediate 27

tert-butyl(5S,6S,9S)-6-(2,3-difluorophenyl)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate

DIAD (0.356 mL, 1.833 mmol) was added to a tetrahydrofuran (5 mL)solution of 4-nitrobenzoic acid (0.306 g, 1.833 mmol), tert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate(0.3578 g, 0.916 mmol) at 0° C. The reaction was stirred overnight whileit was gradually warmed up to room temperature. Lithium hydroxide (0.110g, 4.58 mmol) in 10 mL water was added to the reaction mixture. Thereaction was stirred at room temperature for 5 h. Volatile componentswere removed via vacuum and the crude residue was partitioned betweenethyl acetate and water. The ethyl acetate layer was washed two moretimes by water before dried (sodium sulfate), filtered and concentrated.The crude was purified by flash chromatography eluting with ethylacetate in hexane from 0 to 100%. The product was contaminated with sometriphenyl phosphine oxide but was carried on to the next step withoutfurther purification: MS (ESI)[M+H⁺]=391.15.

Intermediate 28

tert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(1,3-dioxoisoindolin-2-yl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate

DIAD (0.356 mL, 1.832 mmol) was added to a methylene chloride (5 mL)solution of phthalimide (0.270 g, 1.832 mmol), triphenylphosphine (0.481g, 1.832 mmol) and tert-butyl(5S,6S,9S)-6-(2,3-difluorophenyl)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate(0.358 g, 0.916 mmol) at 0° C. The reaction was gradually warmed up toroom temperature and stirred at room temperature for 3 days. Volatilecomponents were removed in vacuo and the crude residue was partitionedbetween ethyl acetate and water. The ethyl acetate layer was washed twomore times with water before being dried (sodium sulfate), filtered andconcentrated. Flash chromatography using ethyl acetate in hexane from 0to 45% gave the desired product (0.541 g, ca 80% purity, 90% for 2steps): MS (ESI)[M+H⁺]=520.16.

Intermediate 29

tert-butyl(5S,6S,9R)-9-amino-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate

A mixture of hydrazine (1 mL, 31.9 mmol) and tert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(1,3-dioxoisoindolin-2-yl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate(0.428 g, 0.823 mmol) in methanol (5 mL) was heated using an oil bath(70° C.) for 4 h. LCMS showed no starting material remaining. Thesolvent was removed via vacuum and the crude residue was partitionedbetween ethyl acetate and water. The ethyl acetate layer was separated,dried (sodium sulfate), filtered and concentrated. Flash chromatographyusing methanol in methylene chloride from 0 to 10% gave the desiredproduct (164 mg, 51%): MS (ESI)[M+H⁺]=390.19; ¹H NMR (400 MHz,CHLOROFORM-d) δ ppm 8.46 (1H, d, J=4.0 Hz), 7.63 (1H, d, J=7.5 Hz), 7.18(1H, dd, J=7.7, 4.9 Hz), 6.92-7.08 (3H, m), 5.24 (1H, t, J=8.8 Hz), 4.50(1H, dd, J=9.3, 2.5 Hz), 3.18 (1H, br. s.), 2.83 (2H, br. s.), 2.04-2.24(3H, m), 1.57 (1H, d, J=9.0 Hz), 1.31 (9H, s), 0.68-0.92 (1H, m).

Intermediate 31

tert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(4-(2-oxo-3-((2-(trimethylsilyl)ethoxy)methyl)-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxamido)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate

In an oven-dried 100 ml round-bottom flask was dissolved1-(piperidin-4-yl)-3-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazo[4,5-b]pyridin-2(3H)-one(52.3 mg, 0.150 mmol) in methylene chloride (5 mL) to give a colorlesssolution. Triethylamine (0.038 mL, 0.28 mmol) was added under nitrogenand the mixture was cooled to −20° C. Trichloromethyl chloroformate(0.012 mL, 0.100 mmol) was added dropwise. The mixture was graduallywarmed up with stirring to 10° C. for 1 h, during which time thesolution became slightly yellow. The reaction was concentrated todryness under vacuum. tert-Butyl(5S,6S,9R)-9-amino-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate(48.7 mg, 0.125 mmol) and triethylamine (0.038 mL, 0.275 mmol) dissolvedin 1 mL tetrahydrofuran (plus 2 mL rinse) was added via canuula at roomtemperature. More triethylamine (0.038 mL, 0.275 mmol) was added. Theresulting faint yellow suspension was stirred under nitrogen overnight.The reaction was diluted with ethyl acetate and washed with water threetimes. The ethyl acetate layer was separated, dried (sodium sulfate),filtered and concentrated. Flash chromatography using methanol inmethylene chloride from 0 to 10% gave the desired product (12 mg, 13%):MS (ESI)[M+H⁺]=764.38.

Example 18

tert-butyl(5S6S,9R)-9-amino-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate

A Methylene chloride (1 mL) solution of tert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(4-(2-oxo-3-((2-(trimethylsilyl)ethoxy)methyl)-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxamido)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate(12 mg, 0.016 mmol) in TFA (0.5 ml, 6 5 mmol) was stirred at roomtemperature overnight. The solvent was removed via vacuum and the cruderesidue was partitioned between ethyl acetate and Sodium bicarbonate(sat). The ethyl acetate layer was separated, dried (sodium sulfate) andconcentrated. The desired product was obtained by prep TLC eluting with10% methanol in methylene chloride: MS (ESI)[M+H⁺]=534.26; ¹H NMR (400MHz, CHLOROFORM-d) δ ppm 8.43-8.48 (1H, m), 8.07-8.12 (1H, m), 8.03-8.06(1H, m), 7.60-7.65 (1H, m), 7.30-7.38 (2H, m), 7.07-7.18 (3H, m),6.96-7.00 (1H, m), 5.21-5.28 (1H, m), 4.56-4.66 (2H, m), 4.33-4.43 (2H,m), 2.91-3.10 (3H, m), 2.24-2.52 (4H, m), 1.94-2.04 (3H, m), 1.43-1.74(5H, m).

Intermediate 32

tert-butyl(5S,6S)-6-(2,3-difluorophenyl)-9-oxo-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate

Dimethylsulfoxide (0.145 mL, 2.049 mmol) was added to a methylenechloride (10 mL) solution of oxalyl chloride (0.768 mL, 1.537 mmol) at−20° C. under nitrogen. The reaction was then cooled to −65° C. andtert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate(0.2 g, 0.512 mmol) was added to the reaction all at once. The reactionwas stirred for 2 h. Triethylamine (0.428 mL, 3.07 mmol) was added tothe reaction mixture and the reaction was allowed to warm to roomtemperature. The reaction was diluted with methylene chloride and washedwith water three times. The methylene chloride layer was separated,dried (sodium sulfate), filtered and concentrated. Flash chromatographyusing ethyl acetate in hexane from 0 to 45% to 65% gave the desiredproduct (199 mg, 73%).

Intermediate 33

(E)-ethyl2-((5S,6S)-5-(tert-butoxycarbonylamino)-6-(2,3-difluorophenyl)-7,8-dihydro-5H-cyclohepta[b]pyridin-9(6H)-ylidene)acetate

A mixture of (carbethoxymethylene)triphenylphosphorane (0.214 g, 0.614mmol) and tert-butyl(5S,6S)-6-(2,3-difluorophenyl)-9-oxo-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate(0.199 g, 0.512 mmol) in toluene (5 mL) was heat to reflux for 18 h. Thesolvent was removed via vacuum and the crude residue was loaded onto asilica gel column directly. Purification was performed by elution withethyl acetate in hexane from 0 to 65% to afford the desired product (138mg, 59%): MS (ESI)[M+H⁺]=459.22; ¹H NMR (400 MHz, CHLOROFORM-d) δ ppm8.53 (1H, dd, J=4.8, 1.3 Hz), 7.70 (1H, d, J=7.5 Hz), 7.32 (1H, dd,J=7.8, 4.8 Hz), 7.15-7.24 (1H, m), 7.05-7.13 (2H, m), 6.39 (1H, t, J=2.3Hz), 5.21-5.31 (1H, m), 4.89-4.99 (1H, m), 4.19 (2H, q, J=7.1 Hz),3.32-3.43 (1H, m), 3.17-3.32 (1H, m), 3.12 (1H, d, J=2.3 Hz), 1.87 (2H,d, J=4.5 Hz), 1.14-1.38 (13H, m).

Intermediate 34, 35

ethyl2-((5S,6S,9S)-5-(tert-butoxycarbonylamino)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl)acetate(34) and ethyl2-((5S,6S,9R)-5-(tert-butoxycarbonylamino)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl)acetate(35)

A mixture of (E)-ethyl((5S,6S)-5-(tert-butoxycarbonylamino)-6-(2,3-difluorophenyl)-7,8-dihydro-5H-cyclohepta[b]pyridin-9(6H)-ylidene)acetate(0.1383 g, 0.302 mmol) and 10% Pd/C (17.4 mg, 0.016 mmol) in methanol (4mL) was stirred under hydrogen (1 atm) at room temperature for 24 h. Thereaction was filtered through a pad of celite and the crude residue wasconcentrated. Flash chromatography using ethyl acetate in hexane from 0to 50% to 85% gave the desired product (35 was more polar than 34): 34(28 mg, 20%): MS (ESI)[M+H⁺]=461.22; ¹H NMR (400 MHz, CHLOROFORM-d) δppm 8.41-8.47 (1H, m), 7.60-7.68 (1H, m), 7.16-7.26 (2H, m), 7.04-7.14(2H, m), 5.39-5.52 (1H, m), 4.65-4.74 (1H, m), 4.16 (2H, d, J=7.3 Hz),3.77-3.89 (1H, m), 3.05-3.25 (2H, m), 2.68-2.80 (1H, m), 2.09-2.25 (1H,m), 1.88-2.06 (2H, m), 1.38-1.50 (1H, m), 1.31 (9H, s), 1.27 (3H, t,J=1.0 Hz). 35 (118 mg, 85%): MS (ESI)[M+H⁺]=461.22; ¹H NMR (400 MHz,CHLOROFORM-d) δ ppm 8.46 (1H, dd, J=4.8, 1.5 Hz), 7.67 (1H, d, J=7.3Hz), 7.17 (1H, dd, J=7.8, 4.8 Hz), 6.96-7.08 (3H, m), 5.12 (2H, m, J=7.0Hz), 4.08-4.18 (2H, m), 3.78 (1H, d, J=4.5 Hz), 3.33 (1H, br. s), 3.20(1H, dd, J=16.2, 7.7 Hz), 2.75 (1H, d, J=7.0 Hz), 1.98-2.07 (1H, m),1.81 (2H, d, J=4.0 Hz), 1.57-1.69 (1H, m), 1.33 (9H, s), 1.21-1.25 (3H,m).

Intermediate 36

2-((5S,6S,9S)-5-(tert-butoxycarbonylamino)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl)aceticacid

A mixture of lithium hydroxide (11.2 mg, 0.468 mmol) and ethyl2-((5S,6S,9S)-5-(tert-butoxycarbonylamino)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl)acetate(27.8 mg, 0.060 mmol) in tetrahydrofuran (3 mL) and water (0.3 mL) wasstirred at room temperature for 24 h. The solvent was removed via highvacuum and the crude product (MS (ESI)[M+H⁺]=433.17) was used as is inthe next step.

Example 19

tert-butyl(5S,6S,9S)-6-(2,3-difluorophenyl)-9-(2-oxo-2-(4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidin-1-yl)ethyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate

DEPBT (26.9 mg, 0.090 mmol) was added to a dimethylformamide (4 mL)solution of2-((5S,6S,9S)-5-(tert-butoxycarbonylamino)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl)aceticacid (25.9 mg, 0.060 mmol),1-(piperidin-4-yl)-1H-imidazo[4,5-b]pyridin-2(3H)-one (19.64 mg, 0.090mmol) at room temperature. After stirring for 20 min, triethylamine(0.013 mL, 0.090 mmol) was added to the reaction mixture. The reactionwas stirred overnight at room temperature. The reaction was diluted withethyl acetate and washed with water three times. The organic layer wasseparated, dried (Sodium sulfate), filtered and concentrated. Flashchromatography using methanol in methylene chloride from 0 to 10% gavethe desired product (24.5 mg, 65%): MS (ESI)[M+H⁺]=633.36; ¹H NMR (400MHz, CHLOROFORM-d) δ ppm 10.32-10.48 (1H, m), 8.45 (1H, d, J=4.5 Hz),8.08 (1H, dd, J=5.3, 1.0 Hz), 7.63-7.74 (1H, m), 7.28-7.34 (2H, m),7.18-7.25 (1H, m), 7.11 (2H, m.), 7.00 (1H, d, J=2.5 Hz), 5.45-5.64 (1H,m), 4.86-4.98 (1H, m), 4.34-4.82 (2H, m), 3.94-4.13 (1H, m), 3.22-3.50(2H, m), 3.07-3.20 (1H, m), 2.72 (2H, m.), 2.21-2.36 (2H, m), 1.95 (3H,m.), 1.32 (9H, d, J=2.5 Hz).

Intermediate 37

2-((5S,6S,9R)-5-(tert-butoxycarbonylamino)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl)aceticacid

A mixture of lithium hydroxide (11.2 mg, 0.468 mmol) and ethyl2-((5S,6S,9R)-5-(tert-butoxycarbonylamino)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl)acetate(118.1 mg, 0.256 mmol) in tetrahydrofuran (3 mL) and water (0.3 mL) wasstirred at room temperature over night. LCMS showed complete conversion.The reaction was dried under high vacuum and the crude product (MS(ESI)[M+H⁺]=433.17) was used as is in the next step.

Example 20

tert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(2-oxo-2-(4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidin-1-yl)ethyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate

DEPBT (0.115 g, 0.384 mmol) was added to a dimethylformamide (4 mL)solution of2-((5S,6S,9R)-5-(tert-butoxycarbonylamino)-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl)aceticacid (0.111 g, 0.256 mmol),1-(piperidin-4-yl)-1H-imidazo[4,5-b]pyridin-2(3H)-one (0.084 g, 0.384mmol) at room temperature. After stirring for 20 min, triethylamine(0.054 mL, 0.384 mmol) was added to the reaction mixture. The reactionwas stirred overnight at room temperature. The reaction was diluted withethyl acetate and washed three times with water. The ethyl acetate layerwas separated, dried (sodium sulfate), filtered and concentrated. Flashchromatography using methanol in methylene chloride from 0 to 10% gavethe desired product (145 mg, 90%):

MS (ESI)[M+H⁺]=633.36; ¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 11.23 (1H,br. s), 8.51 (1H, dd, J=4.8, 1.5 Hz), 8.03-8.14 (1H, m), 7.65-7.78 (1H,m), 7.14-7.41 (2H, m), 6.95-7.08 (4H, m), 5.51-5.72 (1H, m), 5.09-5.22(1H, m), 4.81-4.96 (1H, m), 4.55-4.73 (1H, m), 4.29-4.47 (1H, m),3.90-4.06 (1H, m), 3.34-3.64 (2H, m), 3.13-3.34 (1H, m), 2.56-2.80 (2H,m), 2.08-2.42 (3H, m), 1.53-2.04 (5H, m), 1.31 (9H, s).

Example 21

1-(1-(2-((5S,6S,9R)-5-amino-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl)acetyl)piperidin-4-yl)-1H-imidazo[4,5-b]pyridin-2(3H)-one

To a methylene chloride (5 mL) solution of tert-butyl(5S,6S,9R)-6-(2,3-difluorophenyl)-9-(2-oxo-2-(4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidin-1-yl)ethyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ylcarbamate(0.1452 g, 0.229 mmol) was added TFA (1 ml, 12.98 mmol) at roomtemperature. The reaction was stirred at room temperature for 3 h beforeremoval of the solvent in vacuo. The crude mixture was partitionedbetween ethyl acetate and water. Sodium bicarbonate (sat) was added andthe ethyl acetate layer was separated. The ethyl acetate layer was dried(sodium sulfate), filtered and concentrated. Flash chromatography usingmethanol in methylene chloride from 0 to 10% gave a product that wasstill somewhat impure. The product was further purified by prep TLCeluting with 10% methanol in methylene chloride (25.9 mg, 20%): MS(ESI)[M+H⁺]=533.29; ¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.47 (1H, td,J=5.3, 3.5 Hz), 8.09 (1H, d, J=5.3 Hz), 7.49-7.58 (1H, m), 7.27-7.34(1H, m), 7.18 (1H, ddd, J=15.3, 7.4, 4.9 Hz), 6.95-7.10 (4H, m), 4.87(1H, d, J=13.1 Hz), 4.57-4.76 (1H, m), 4.44 (1H, d, J=13.1 Hz),4.10-4.33 (2H, m), 3.46-3.67 (1H, m), 3.20-3.40 (2H, m), 2.39-2.79 (3H,m), 1.50-2.33 (9H, m).

It will be evident to one skilled in the art that the present disclosureis not limited to the foregoing illustrative examples, and that it canbe embodied in other specific forms without departing from the essentialattributes thereof. It is therefore desired that the examples beconsidered in all respects as illustrative and not restrictive,reference being made to the appended claims, rather than to theforegoing examples, and all changes which come within the meaning andrange of equivalency of the claims are therefore intended to be embracedtherein.

1. The compound(6R,9R)-6-(2,3-Difluorophenyl)-6-hydroxy-5-oxo-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylateor a pharmaceutically acceptable salt thereof.